DIY ±18VDC to power a dead cordless drill

Hi! My last battery died on my cordless drill and i'm trying to transform it to a corded drill. My plan was to use a microvawe transformer along with a bridge rectifier (KBPC5010  Bridge Rectifier Diode, KBPC Series, Single, 1 kV, 50 A, 1.2 V, Module, 4) to power the drill. 120VAC from the wall to, I wish, 12to18VDC. The problem with this is the voltage given by the output of the microwave transformer is of only ±3VAC. Any sugestion?

Topic by rudecam   |  last reply


Do Amps matter?!?

Ok, I need a charger for my motorolla two way radios. I have the dock, only need a DC power supply. on one of them it states "18Volts DC +/- 20%, 15.3 watts" .Lets say I get 18VDC 1amp power supply, that's 18W,it means it's an overkill? or 15V 2Amps? As I understand, usually amps don't matter, as the item draws as much as it needs, but since it is a charger.. Cheers for the teh help!

Question by zhgutas   |  last reply



12VDC to 18VDC Hard wire tools through the charger Answered

I am working off grid and I want to run 18V tools directly off my deep cycles I have powered by solar. I have a few dead ryobi one batt. laying around that I could open up to use. My question is can I use a 12V DC charger for the 18v batts to power an 18v grinder? I would gut the batteries and wire the two together put one in the charger one in the grinder. Too much amperage for the charger?  

Question by clow57   |  last reply


When using a step-down transformer (120vac-18vdc), will I need to limit the current going to the motor?

Attempting to modify an old rechargeable battery for power tools into a power source that can be plugged into the wall and inserted into the power tool. I know that step down transformers raise the current, but I am unsure if this will be an issue. Either way... What is the best way to reduce current while not reducing voltage? Is that possible?

Question by gmecomber   |  last reply


LED Wiring, Over Amp Burnout? Answered

Hi everyone, hope someone can help? I just started playing around with some LED lights, trying to make a really bright Flounder light that can last at least 6-8 hours on the supplied battery. I was told if I used a "step-down", I wouldn't need resistors, (since the step-down does this in an essence), which I haven't, But the step-down keeps burning up? Here's the set-up I've been playing with... - 18vdc (power drill) battery. (unknown amps). - Step-down driver.... input 8vdc - 36vdc, output 1.5vdc - 36vdc - 3w LED Cree :                            ~ Reverse Voltage: 5.0 V                           ~ DC Forward Voltage: Typical: 3.8V Max: 4.2 VD                           ~ DC Forward Current: 700mA                           ~ Luminous Intensity: 170-190lm                                                           I use a volt meter to tune the Driver to a constant 4vdc to drive the LED. And the driver burns up and then the bulb after about 5 minutes. I was told I needed to add Ceramic Resistors, between the driver and battery, and between the driver and LED. (But what size?) I was also told I don't need extra resistors because of the driver? Which is Right? Or should I just add resistors between the battery and LED and do away with the Driver completely? Also, what is meant by "Reverse Voltage"? I have a 6vdc battery with a 4.5 amp capacity. But I want to use the 18vdc battery longer use, time wise. This is why I have the Driver, when 1 battery deletes, hook up the other one. I'd like to put 3 - 3w (180L) LED bulbs together, and run them off the 6vdc and/or the 18vdc battery so the LED's will last for at least 6-8 hours on 1 charge. I want to use either the 6vdc and/or the 18vdc battery because they are lightweight. I could go with 1w LED's so long as I can get the brightness needed to light up a distance of about 12' underwater to see a Flounder, and get 6-8 hours usage. Any help would be appreciated.

Question by Atomizer   |  last reply


how to power my hobbie motor?

I bought a motor from radioshack ( Catalog #: 273-256 ) it runs off 3 differant voltages 9,12,and 18 volts at 380,400, and 430mA resectively. No load: 9VDC 380mA current max., 11000± 15% speed, 150g.cm min. torque No load: 12VDC 400mA current max., 15200± 15% speed, 190g.cm min. torqu No load: 18VDC 430mA current max., 24000± 15% speed, 290g.cm min. torque i need the torque of 18v at 430mA but im not sure how to power this without a whole lot of work, i need a way of simply hooking up a few wires and maybe solder them together.

Question by pmk222   |  last reply


Old LCD Backlight...What to do...

I have a typical CCFL-lit LCD backlight that I tore out of an ancient, dying laptop with an ancient, dying screen. The backlight is roughly 25.5cm x 19 cm (9 7/8" x 7 1/2") and about .5cm (1/4") thick. When around 18VDC is applied to the inverter, the whole rectangle lights up with a perfectly even, white, light. I've been trying to come up with something cool to do with it. So far, these ideas have included: -With a piece of protective plastic, a small lightbox for tracing or viewing negatives/slides -Mounted over a desk for a really cool lamp -Illuminated sign Does anyone have any brilliant ideas for what to build with this? A project worthy of the geekiness or the materials?

Topic by CameronSS   |  last reply


What speakers can go with a 7W mono amplifier? Answered

I have a bunch of speakers lying around, and I recently bought an amplifier kit from Velleman. Specs: Music output: 7W/4ohm RMS output: 3.5W/4ohm or 2W/8ohm Total harmonic distortion: 0.05% (1W/1KHz) Frequency response: 20Hz-20KHz (-3dB) Input sensitivity: 40mV/150Kohm Signal/noise ratio: 86dB (A weighted) Power supply: 8-18VDC/0.5A I have two 8ohm 2W speakers, and two speakers that I can't seem to find the specs for, but it's the same speakers in the picture. I was just wondering if I'd be able to wire up the two 8ohm speakers together and connect it to the amp, but from the specs of the amp, I'm guessing I can't do that? And out of curiosity, what happens when you wire up speakers that don't suit the amp? Also, would 4AA batteries be sufficient enough to power this? And any extra advice/input would be greatly appreciated!

Question by Justin Lam   |  last reply


Is someone willing to give me a good amount of technical advice concerning heat dissipation using a Peltier device ?

Ok, I have a laptop that I use to play many videogames with, and as you can imagine, it has an overheating is a problem. I have software that monitors the GPU and CPU temperatures while I play. The GPU and CPU are rated at a 100c max temperature. Now that the summer season has started, my laptop gets hotter and hotter as I play. I am usually forced to Under-volt my computer so that it stays below safe temperatures. Now, I was digging around online and came across something called a "Peltier device". It is a small ceramic plate (with electrical nodes inside) that when electrified, transfers the heat from one side to the other. The peltier I got is rated at 545 watts, 32 amps, and 18vdc, and gets as cold as -60c, 150c. I ordered a desktop power supply online, along with 2 CPU cooling systems. (I.E.  2x Professional grade heat-sink, and 2x 120mm fan) The Power supply outputs 430watts, 28 amps, and 12vdc. I planned on taking these parts and simply sandwiching the peltier between 2 heatsinks, having 1 hot heatsink+fan and 1 cold heatsink+fan. I planned on pumping the cold air into the air intake on the bottom of my laptop, and just pump the hot air into the room.  Unfortunately, the problem I face (and this is a really stupid mistake) was that I did not measure out this whole assembly. It turns out, the peltier face plates are roughly 2.5" x 2.5", whereas the heat-transfer faceplate of the heatsinks are only about 1.5" x 1.5". Now, I wired this all up, and put it all together, ignoring the parts of the peltier that were hanging off and lo' and behold, the peltier worked as designed, one side got extremely cold, and the other got hot. The only problem is, over time, since nothing was drawing the heat away from the edges of the hot side, it transferred over to the cold side, thus warming it up to about room temperature, negating the entire purpose of the contraption.  This is the part that I need help on, would simply taking some aluminum plates that are large enough to cover the entire surface of the peltier, smother both sides in my remaining thermal compound, and then connect this aluminum (with more thermal compound) to the heatsink? This contraption is essentially meant to be a laptop cooling pad. Mounted inside of an old computer case. So it needs to be mobile (IE, liquid cooling is not an option). Can anyone think of a better solution to this? 

Question by schwerlin   |  last reply


JavaScript errors on recently posted Questions -- cache server?

Three Questions posted this morning all come up with "the same" ERROR 500 from JavaScript, included at the end of this topic: Why does my multimeter read 18vdc on a 12vdc walwart? Why does my multimeter read 18Vdc on a 12Vdc wall wart? Only one armpit smells? Other Questions, posted both before and since those three, appear to be just fine. Was there a server glitch? Caught in the filters? Deleted by the authors? UPDATE:  More than just these three questions are affected, but there is no clear pattern.  Some Questions seem to be fine, others generate the error.  Perhaps one of the cache servers is hosed?   javax.servlet.ServletException: javax.servlet.jsp.JspException: ServletException in '/common/layout3col.jspx': java.lang.reflect.InvocationTargetException at com.caucho.jsp.PageContextImpl.handlePageException(PageContextImpl.java:1120) at _jsp._pages._error._error__jsp._jspService(pages/error/error.jsp:9) at com.caucho.jsp.JavaPage.service(JavaPage.java:60) at com.caucho.jsp.Page.pageservice(Page.java:570) at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:179) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350) at com.instructables.servlet.ErrorServlet.service(ErrorServlet.java:68) at javax.servlet.http.HttpServlet.service(HttpServlet.java:92) at com.caucho.server.dispatch.ServletFilterChain.doFilter(ServletFilterChain.java:106) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:277) at com.caucho.server.webapp.RequestDispatcherImpl.error(RequestDispatcherImpl.java:113) at com.caucho.server.webapp.ErrorPageManager.sendServletError(ErrorPageManager.java:362) at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:175) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.http.HttpRequest.handleRequest(HttpRequest.java:274) at com.caucho.server.port.TcpConnection.run(TcpConnection.java:514) at com.caucho.util.ThreadPool.runTasks(ThreadPool.java:527) at com.caucho.util.ThreadPool.run(ThreadPool.java:449) at java.lang.Thread.run(Thread.java:619) Caused by: javax.servlet.jsp.JspException: ServletException in '/common/layout3col.jspx': java.lang.reflect.InvocationTargetException at org.apache.tiles.taglib.InsertTag$InsertHandler.doEndTag(InsertTag.java:923) at org.apache.tiles.taglib.InsertTag.doEndTag(InsertTag.java:457) at _jsp._pages._error._error__jsp._jspService(pages/error/error.jsp:9) at com.caucho.jsp.JavaPage.service(JavaPage.java:60) at com.caucho.jsp.Page.pageservice(Page.java:570) at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:179) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350) at com.instructables.servlet.ErrorServlet.service(ErrorServlet.java:68) at javax.servlet.http.HttpServlet.service(HttpServlet.java:92) at com.caucho.server.dispatch.ServletFilterChain.doFilter(ServletFilterChain.java:106) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:277) at com.caucho.server.webapp.RequestDispatcherImpl.error(RequestDispatcherImpl.java:113) at com.caucho.server.webapp.ErrorPageManager.sendServletError(ErrorPageManager.java:362) at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:175) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.http.HttpRequest.handleRequest(HttpRequest.java:274) at com.caucho.server.port.TcpConnection.run(TcpConnection.java:514) at com.caucho.util.ThreadPool.runTasks(ThreadPool.java:527) at com.caucho.util.ThreadPool.run(ThreadPool.java:449) at java.lang.Thread.run(Thread.java:619) Caused by: javax.servlet.ServletException: javax.servlet.jsp.el.ELException: java.lang.reflect.InvocationTargetException at com.caucho.jsp.PageContextImpl.handlePageException(PageContextImpl.java:1120) at _jsp._common._nav__jsp._jspService(_nav__jsp.java:237) at com.caucho.jsp.JavaPage.service(JavaPage.java:60) at com.caucho.jsp.Page.pageservice(Page.java:570) at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:179) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350) at com.caucho.jsp.PageContextImpl.include(PageContextImpl.java:933) at _jsp._common._layout3col__jspx._jspService(file:/home/instruct/deploy/instructables/common/layout3col.jspx:193) at com.caucho.jsp.JavaPage.service(JavaPage.java:60) at com.caucho.jsp.Page.pageservice(Page.java:570) at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:179) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350) at com.caucho.jsp.PageContextImpl.include(PageContextImpl.java:933) at com.caucho.jsp.PageContextImpl.include(PageContextImpl.java:870) at org.apache.tiles.TilesUtilImpl.doInclude(TilesUtilImpl.java:143) at org.apache.tiles.TilesUtil.doInclude(TilesUtil.java:149) at org.apache.tiles.taglib.InsertTag.doInclude(InsertTag.java:760) at org.apache.tiles.taglib.InsertTag$InsertHandler.doEndTag(InsertTag.java:892) at org.apache.tiles.taglib.InsertTag.doEndTag(InsertTag.java:457) at _jsp._pages._error._error__jsp._jspService(pages/error/error.jsp:9) at com.caucho.jsp.JavaPage.service(JavaPage.java:60) at com.caucho.jsp.Page.pageservice(Page.java:570) at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:179) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350) at com.instructables.servlet.ErrorServlet.service(ErrorServlet.java:68) at javax.servlet.http.HttpServlet.service(HttpServlet.java:92) at com.caucho.server.dispatch.ServletFilterChain.doFilter(ServletFilterChain.java:106) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:277) at com.caucho.server.webapp.RequestDispatcherImpl.error(RequestDispatcherImpl.java:113) at com.caucho.server.webapp.ErrorPageManager.sendServletError(ErrorPageManager.java:362) at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:175) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.http.HttpRequest.handleRequest(HttpRequest.java:274) at com.caucho.server.port.TcpConnection.run(TcpConnection.java:514) at com.caucho.util.ThreadPool.runTasks(ThreadPool.java:527) at com.caucho.util.ThreadPool.run(ThreadPool.java:449) at java.lang.Thread.run(Thread.java:619) Caused by: javax.servlet.jsp.el.ELException: java.lang.reflect.InvocationTargetException at com.caucho.el.StaticMethodExpr.evalMethod(StaticMethodExpr.java:142) at com.caucho.el.FunctionExpr.evalObject(FunctionExpr.java:71) at com.caucho.el.Expr.print(Expr.java:325) at _jsp._common._nav__jsp._jspService(common/nav.jsp:186) at com.caucho.jsp.JavaPage.service(JavaPage.java:60) at com.caucho.jsp.Page.pageservice(Page.java:570) at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:179) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350) at com.caucho.jsp.PageContextImpl.include(PageContextImpl.java:933) at _jsp._common._layout3col__jspx._jspService(file:/home/instruct/deploy/instructables/common/layout3col.jspx:193) at com.caucho.jsp.JavaPage.service(JavaPage.java:60) at com.caucho.jsp.Page.pageservice(Page.java:570) at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:179) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350) at com.caucho.jsp.PageContextImpl.include(PageContextImpl.java:933) at com.caucho.jsp.PageContextImpl.include(PageContextImpl.java:870) at org.apache.tiles.TilesUtilImpl.doInclude(TilesUtilImpl.java:143) at org.apache.tiles.TilesUtil.doInclude(TilesUtil.java:149) at org.apache.tiles.taglib.InsertTag.doInclude(InsertTag.java:760) at org.apache.tiles.taglib.InsertTag$InsertHandler.doEndTag(InsertTag.java:892) at org.apache.tiles.taglib.InsertTag.doEndTag(InsertTag.java:457) at _jsp._pages._error._error__jsp._jspService(pages/error/error.jsp:9) at com.caucho.jsp.JavaPage.service(JavaPage.java:60) at com.caucho.jsp.Page.pageservice(Page.java:570) at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:179) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350) at com.instructables.servlet.ErrorServlet.service(ErrorServlet.java:68) at javax.servlet.http.HttpServlet.service(HttpServlet.java:92) at com.caucho.server.dispatch.ServletFilterChain.doFilter(ServletFilterChain.java:106) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:277) at com.caucho.server.webapp.RequestDispatcherImpl.error(RequestDispatcherImpl.java:113) at com.caucho.server.webapp.ErrorPageManager.sendServletError(ErrorPageManager.java:362) at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:175) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.http.HttpRequest.handleRequest(HttpRequest.java:274) at com.caucho.server.port.TcpConnection.run(TcpConnection.java:514) at com.caucho.util.ThreadPool.runTasks(ThreadPool.java:527) at com.caucho.util.ThreadPool.run(ThreadPool.java:449) at java.lang.Thread.run(Thread.java:619) Caused by: java.lang.reflect.InvocationTargetException at sun.reflect.GeneratedMethodAccessor99.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at com.caucho.el.StaticMethodExpr.evalMethod(StaticMethodExpr.java:133) at com.caucho.el.FunctionExpr.evalObject(FunctionExpr.java:71) at com.caucho.el.Expr.print(Expr.java:325) at _jsp._common._nav__jsp._jspService(common/nav.jsp:186) at com.caucho.jsp.JavaPage.service(JavaPage.java:60) at com.caucho.jsp.Page.pageservice(Page.java:570) at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:179) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350) at com.caucho.jsp.PageContextImpl.include(PageContextImpl.java:933) at _jsp._common._layout3col__jspx._jspService(file:/home/instruct/deploy/instructables/common/layout3col.jspx:193) at com.caucho.jsp.JavaPage.service(JavaPage.java:60) at com.caucho.jsp.Page.pageservice(Page.java:570) at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:179) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350) at com.caucho.jsp.PageContextImpl.include(PageContextImpl.java:933) at com.caucho.jsp.PageContextImpl.include(PageContextImpl.java:870) at org.apache.tiles.TilesUtilImpl.doInclude(TilesUtilImpl.java:143) at org.apache.tiles.TilesUtil.doInclude(TilesUtil.java:149) at org.apache.tiles.taglib.InsertTag.doInclude(InsertTag.java:760) at org.apache.tiles.taglib.InsertTag$InsertHandler.doEndTag(InsertTag.java:892) at org.apache.tiles.taglib.InsertTag.doEndTag(InsertTag.java:457) at _jsp._pages._error._error__jsp._jspService(pages/error/error.jsp:9) at com.caucho.jsp.JavaPage.service(JavaPage.java:60) at com.caucho.jsp.Page.pageservice(Page.java:570) at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:179) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350) at com.instructables.servlet.ErrorServlet.service(ErrorServlet.java:68) at javax.servlet.http.HttpServlet.service(HttpServlet.java:92) at com.caucho.server.dispatch.ServletFilterChain.doFilter(ServletFilterChain.java:106) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:277) at com.caucho.server.webapp.RequestDispatcherImpl.error(RequestDispatcherImpl.java:113) at com.caucho.server.webapp.ErrorPageManager.sendServletError(ErrorPageManager.java:362) at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:175) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.http.HttpRequest.handleRequest(HttpRequest.java:274) at com.caucho.server.port.TcpConnection.run(TcpConnection.java:514) at com.caucho.util.ThreadPool.runTasks(ThreadPool.java:527) at com.caucho.util.ThreadPool.run(ThreadPool.java:449) at java.lang.Thread.run(Thread.java:619) Caused by: java.lang.NullPointerException at com.instructables.taglib.Functions.translateCategoryName(Functions.java:1008)

Topic by kelseymh   |  last reply


Another Error 500

When trying to read this question: https://www.instructables.com/answers/Why-does-my-multimeter-read-18vdc-on-a-12vdc-walwa/ I got an "error 500" message: ------------------------------------------------- 500 Servlet Exception javax.servlet.ServletException: javax.servlet.jsp.JspException: ServletException in '/common/layout3col.jspx': java.lang.reflect.InvocationTargetException at com.caucho.jsp.PageContextImpl.handlePageException(PageContextImpl.java:1120) at _jsp._pages._error._error__jsp._jspService(pages/error/error.jsp:9) at com.caucho.jsp.JavaPage.service(JavaPage.java:60) at com.caucho.jsp.Page.pageservice(Page.java:570) at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:179) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350) at com.instructables.servlet.ErrorServlet.service(ErrorServlet.java:68) at javax.servlet.http.HttpServlet.service(HttpServlet.java:92) at com.caucho.server.dispatch.ServletFilterChain.doFilter(ServletFilterChain.java:106) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:277) at com.caucho.server.webapp.RequestDispatcherImpl.error(RequestDispatcherImpl.java:113) at com.caucho.server.webapp.ErrorPageManager.sendServletError(ErrorPageManager.java:362) at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:175) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.http.HttpRequest.handleRequest(HttpRequest.java:274) at com.caucho.server.port.TcpConnection.run(TcpConnection.java:514) at com.caucho.util.ThreadPool.runTasks(ThreadPool.java:527) at com.caucho.util.ThreadPool.run(ThreadPool.java:449) at java.lang.Thread.run(Thread.java:619) Caused by: javax.servlet.jsp.JspException: ServletException in '/common/layout3col.jspx': java.lang.reflect.InvocationTargetException at org.apache.tiles.taglib.InsertTag$InsertHandler.doEndTag(InsertTag.java:923) at org.apache.tiles.taglib.InsertTag.doEndTag(InsertTag.java:457) at _jsp._pages._error._error__jsp._jspService(pages/error/error.jsp:9) at com.caucho.jsp.JavaPage.service(JavaPage.java:60) at com.caucho.jsp.Page.pageservice(Page.java:570) at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:179) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350) at com.instructables.servlet.ErrorServlet.service(ErrorServlet.java:68) at javax.servlet.http.HttpServlet.service(HttpServlet.java:92) at com.caucho.server.dispatch.ServletFilterChain.doFilter(ServletFilterChain.java:106) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:277) at com.caucho.server.webapp.RequestDispatcherImpl.error(RequestDispatcherImpl.java:113) at com.caucho.server.webapp.ErrorPageManager.sendServletError(ErrorPageManager.java:362) at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:175) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.http.HttpRequest.handleRequest(HttpRequest.java:274) at com.caucho.server.port.TcpConnection.run(TcpConnection.java:514) at com.caucho.util.ThreadPool.runTasks(ThreadPool.java:527) at com.caucho.util.ThreadPool.run(ThreadPool.java:449) at java.lang.Thread.run(Thread.java:619) Caused by: javax.servlet.ServletException: javax.servlet.jsp.el.ELException: java.lang.reflect.InvocationTargetException at com.caucho.jsp.PageContextImpl.handlePageException(PageContextImpl.java:1120) at _jsp._common._nav__jsp._jspService(_nav__jsp.java:237) at com.caucho.jsp.JavaPage.service(JavaPage.java:60) at com.caucho.jsp.Page.pageservice(Page.java:570) at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:179) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350) at com.caucho.jsp.PageContextImpl.include(PageContextImpl.java:933) at _jsp._common._layout3col__jspx._jspService(file:/home/instruct/deploy/instructables/common/layout3col.jspx:193) at com.caucho.jsp.JavaPage.service(JavaPage.java:60) at com.caucho.jsp.Page.pageservice(Page.java:570) at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:179) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350) at com.caucho.jsp.PageContextImpl.include(PageContextImpl.java:933) at com.caucho.jsp.PageContextImpl.include(PageContextImpl.java:870) at org.apache.tiles.TilesUtilImpl.doInclude(TilesUtilImpl.java:143) at org.apache.tiles.TilesUtil.doInclude(TilesUtil.java:149) at org.apache.tiles.taglib.InsertTag.doInclude(InsertTag.java:760) at org.apache.tiles.taglib.InsertTag$InsertHandler.doEndTag(InsertTag.java:892) at org.apache.tiles.taglib.InsertTag.doEndTag(InsertTag.java:457) at _jsp._pages._error._error__jsp._jspService(pages/error/error.jsp:9) at com.caucho.jsp.JavaPage.service(JavaPage.java:60) at com.caucho.jsp.Page.pageservice(Page.java:570) at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:179) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350) at com.instructables.servlet.ErrorServlet.service(ErrorServlet.java:68) at javax.servlet.http.HttpServlet.service(HttpServlet.java:92) at com.caucho.server.dispatch.ServletFilterChain.doFilter(ServletFilterChain.java:106) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:277) at com.caucho.server.webapp.RequestDispatcherImpl.error(RequestDispatcherImpl.java:113) at com.caucho.server.webapp.ErrorPageManager.sendServletError(ErrorPageManager.java:362) at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:175) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.http.HttpRequest.handleRequest(HttpRequest.java:274) at com.caucho.server.port.TcpConnection.run(TcpConnection.java:514) at com.caucho.util.ThreadPool.runTasks(ThreadPool.java:527) at com.caucho.util.ThreadPool.run(ThreadPool.java:449) at java.lang.Thread.run(Thread.java:619) Caused by: javax.servlet.jsp.el.ELException: java.lang.reflect.InvocationTargetException at com.caucho.el.StaticMethodExpr.evalMethod(StaticMethodExpr.java:142) at com.caucho.el.FunctionExpr.evalObject(FunctionExpr.java:71) at com.caucho.el.Expr.print(Expr.java:325) at _jsp._common._nav__jsp._jspService(common/nav.jsp:186) at com.caucho.jsp.JavaPage.service(JavaPage.java:60) at com.caucho.jsp.Page.pageservice(Page.java:570) at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:179) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350) at com.caucho.jsp.PageContextImpl.include(PageContextImpl.java:933) at _jsp._common._layout3col__jspx._jspService(file:/home/instruct/deploy/instructables/common/layout3col.jspx:193) at com.caucho.jsp.JavaPage.service(JavaPage.java:60) at com.caucho.jsp.Page.pageservice(Page.java:570) at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:179) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350) at com.caucho.jsp.PageContextImpl.include(PageContextImpl.java:933) at com.caucho.jsp.PageContextImpl.include(PageContextImpl.java:870) at org.apache.tiles.TilesUtilImpl.doInclude(TilesUtilImpl.java:143) at org.apache.tiles.TilesUtil.doInclude(TilesUtil.java:149) at org.apache.tiles.taglib.InsertTag.doInclude(InsertTag.java:760) at org.apache.tiles.taglib.InsertTag$InsertHandler.doEndTag(InsertTag.java:892) at org.apache.tiles.taglib.InsertTag.doEndTag(InsertTag.java:457) at _jsp._pages._error._error__jsp._jspService(pages/error/error.jsp:9) at com.caucho.jsp.JavaPage.service(JavaPage.java:60) at com.caucho.jsp.Page.pageservice(Page.java:570) at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:179) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350) at com.instructables.servlet.ErrorServlet.service(ErrorServlet.java:68) at javax.servlet.http.HttpServlet.service(HttpServlet.java:92) at com.caucho.server.dispatch.ServletFilterChain.doFilter(ServletFilterChain.java:106) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:277) at com.caucho.server.webapp.RequestDispatcherImpl.error(RequestDispatcherImpl.java:113) at com.caucho.server.webapp.ErrorPageManager.sendServletError(ErrorPageManager.java:362) at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:175) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.http.HttpRequest.handleRequest(HttpRequest.java:274) at com.caucho.server.port.TcpConnection.run(TcpConnection.java:514) at com.caucho.util.ThreadPool.runTasks(ThreadPool.java:527) at com.caucho.util.ThreadPool.run(ThreadPool.java:449) at java.lang.Thread.run(Thread.java:619) Caused by: java.lang.reflect.InvocationTargetException at sun.reflect.GeneratedMethodAccessor99.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at com.caucho.el.StaticMethodExpr.evalMethod(StaticMethodExpr.java:133) at com.caucho.el.FunctionExpr.evalObject(FunctionExpr.java:71) at com.caucho.el.Expr.print(Expr.java:325) at _jsp._common._nav__jsp._jspService(common/nav.jsp:186) at com.caucho.jsp.JavaPage.service(JavaPage.java:60) at com.caucho.jsp.Page.pageservice(Page.java:570) at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:179) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350) at com.caucho.jsp.PageContextImpl.include(PageContextImpl.java:933) at _jsp._common._layout3col__jspx._jspService(file:/home/instruct/deploy/instructables/common/layout3col.jspx:193) at com.caucho.jsp.JavaPage.service(JavaPage.java:60) at com.caucho.jsp.Page.pageservice(Page.java:570) at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:179) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350) at com.caucho.jsp.PageContextImpl.include(PageContextImpl.java:933) at com.caucho.jsp.PageContextImpl.include(PageContextImpl.java:870) at org.apache.tiles.TilesUtilImpl.doInclude(TilesUtilImpl.java:143) at org.apache.tiles.TilesUtil.doInclude(TilesUtil.java:149) at org.apache.tiles.taglib.InsertTag.doInclude(InsertTag.java:760) at org.apache.tiles.taglib.InsertTag$InsertHandler.doEndTag(InsertTag.java:892) at org.apache.tiles.taglib.InsertTag.doEndTag(InsertTag.java:457) at _jsp._pages._error._error__jsp._jspService(pages/error/error.jsp:9) at com.caucho.jsp.JavaPage.service(JavaPage.java:60) at com.caucho.jsp.Page.pageservice(Page.java:570) at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:179) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:485) at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:350) at com.instructables.servlet.ErrorServlet.service(ErrorServlet.java:68) at javax.servlet.http.HttpServlet.service(HttpServlet.java:92) at com.caucho.server.dispatch.ServletFilterChain.doFilter(ServletFilterChain.java:106) at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.webapp.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:277) at com.caucho.server.webapp.RequestDispatcherImpl.error(RequestDispatcherImpl.java:113) at com.caucho.server.webapp.ErrorPageManager.sendServletError(ErrorPageManager.java:362) at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:175) at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229) at com.caucho.server.http.HttpRequest.handleRequest(HttpRequest.java:274) at com.caucho.server.port.TcpConnection.run(TcpConnection.java:514) at com.caucho.util.ThreadPool.runTasks(ThreadPool.java:527) at com.caucho.util.ThreadPool.run(ThreadPool.java:449) at java.lang.Thread.run(Thread.java:619) Caused by: java.lang.NullPointerException at com.instructables.taglib.Functions.translateCategoryName(Functions.java:1008) Resin Professional 3.0.28 (built Mon, 18 May 2009 02:21:41 PDT)

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