Vdc to Vac

Hi there hope someone will have some info....anyway what I'm after is a schematic or similar for an inverter 13.8Vdc to 2000Vac with a variable square wave oscillator so i can adjust the frequency possibly incorporating a 555 will be @ 50% duty

Topic by Narnies   |  last reply



If you connect the 12Vdc and -12Vdc on a desktop PSU do you get 24 Volts?

I used to understand more about electricity and electronics, i swear. I have used the yellow-to-red (+12 to +5 Vdc) method to create 7 volt dc connections for my desktop and xbox fans. I understand the concept of differences in voltage. Do these concepts carry over into negative voltage available on the ATX power supplies?

Question by Andale_The_Great   |  last reply


how 150-300VAC 50-60Hz 0.15A adapter work on 110~120VDC?

In India local trains are using DC to power up lights and fans inside the bogies.sum bogeys have power socket to charge mobile or laptops.but that socket is powered by  110~120VDC .is that possible. AC adapters can work DC

Question by vina1991   |  last reply


Need help with DMX512 to Analog 0-10VDC Decoder

I am looking to *update* some old strobe lights that my theater uses to be able to control them through our DMX control board.  They have 2 analog 0-10V inputs to control the flash rate and the intensity.  I am looking for the simplest solution as we do not have a lot of money to throw at this project.  I have some experience in electronics as well as working with arduino, but not enough to tackle this job by myself.   Any thoughts on this would be appreciated!  Attaching the control spec sheet. Tom

Topic by AJackOfAllTrades   |  last reply


Using AC to operate a automotive 12 VDC relay

My question is:  can a typical 12 vdc automotive relay be operated (voltage across terminals 85-86)? I am building a car from a riding lawn mower for our grandson.  I want to operate lights from the 12 VDC circuit but I need a signal voltage to actuate the relay across relay terminals 85-86.  I would like to use the existing AC powered light(s) voltage for this purpose?  Possible?

Topic by mndb1971   |  last reply


How to step down and convert wall outlet to 24 VDC?

Hi I am working on a project and i need to convert 120 VAC from a wall outlet to 24 VDC to run my device. I was wondering if anyone has a suggestion if i should first transform the 120 VAC to 24 VAC and then convert the 24 VAC to 24 VDC? or if there is a 120 VAC to 24 VDC with a normal wall plug for sale. 

Topic by mkapler13   |  last reply


220 VAC to 12 VDC with minimum no-load wastage? Answered

Hi,I want to convert 220 VAC to 12 VDC without using a transformer since they consume power even when a load isn't connected to the secondary output.So this is how its to be-A 12 volt dc supply should be available,which will be fed to a relay once a switch is set 'ON'.I could easily depend on a transformer but this 12 VDC supply is to be available always and can't afford the wastage.pls suggest an alternative(and FYI a battery is not applicable in this situation).

Question by Adarsh_tronix   |  last reply


how do i connect DC devices to my DC generator?

I got an old treadmill with a blown board, stripped out all the electronics ( kept it) with the intention of using the treadmill as a generator only - knowing that the engines are good - the engine is rated to 180VDC, and i have so far at a nice easy walk noted 100VDC on my multimeter hooked directly up to the terminals. it seems clear to me when i plug my 24v fan in and walk that while it spins well and faster the faster i walk - it doesnt need 100vdc and will probably blow eventually - so i must need a voltage regulator?>> or the like.... 1.) how to make / buy one easily? 2.) can i charge car battery from it - do i need any kind of regulation/ charge controller  if i was doing that - am i correct in believing the more load i wire in ( perhaps on a sliding scale or some kind of switch) the more resistance will be generated to the walker? thanks - will

Question by agatornz   |  last reply


Zener Set Voltage Signal Circuit (help)

Hey Everyone- I have been researching on ways to send out an electric signal to trip a relay to shut off my battery charger. I did find some simple circuits and I did the math for what I would need and could not find big enough zener diodes and resistors. Battery+(Resistor)(Zener Diode)(Relay Input)(Battery-) I need this circuit to send a 8.2 or 10Volt 15mA signal to my Relay when the batteries reach 235 volts. Following are the SPECS for the Input signal on my Relay::: Control Voltage Range 3-32 Vdc 90-280 Vrms (60Hz) 18-36 Vrms/Vdc Max. Reverse Voltage -32 Vdc - - - - - - Max. Turn-On Voltage 3.0 Vdc 90 Vrms 18 Vrms/Vdc Min. Turn-Off Voltage 1.0 Vdc 10 Vrms 4.0 Vrms/Vdc Nominal Input Impedance 1500 Ohms 60K Ohms 9.0K Ohms Typical Input Current 3.4mA @ 5 Vdc, 20mA @ 28Vdc 2mA @ 120 Vrms, 4mA @ 240 Vrms 3mA @ 24 V Any help on this would be great Thanks!

Topic by rc_rs_ss   |  last reply


How many VDC do I need to flash burn AA nicads?

I have 40 or 50 AA nicads and was wondering how to flash them to burn the crystals out of them.

Question by kricketone   |  last reply


Computer fan wiring issue? Answered

I just bought 3..SONYMODEL SFF22C10 VDC 0.51 ADC BRUSHLESS FANs..from Princess Auto in the surplus section. It was just labled "Sony Blowfan", so I assumed that they were computer fans, so I could use them with my server I'm setting up. It turns out my server's motherboard doesn't have the correct outlet for the fans plugs. In fact, I haven't ever seen a fan with a plug as small as this is! I'm assuming that the red wire is positive+, the black is ground or negative-, and the white lets the motherboard control the speed. I will only need the + and -, I want the fan to go full blast all the time. It is only rated for 10 VDC, but could I hook up all three of the fans to one of the extra hard drive 12 VDC power cables (yellow and black wires)? Or do I need a resistor, with how much resistance? Also, so do I make the fan run full blast off of only power, when it needs the white wire to have a signal?This question has been answered! See if you can help me with the next step of my project.https://www.instructables.com/answers/Server-Airflow-Help/-Shadow Ops

Question by Arbitror   |  last reply


I have an old Epson,modG760A digital camera.My problem is I need a 3.4VDC transformer.

I have a 3.7 VDC wallwart that I think I can use but cannot find the right pin to fit.

Question by unclelar   |  last reply


Opto Isolator? Answered

From everything i have read it looks to me like you can use an opto isolator with different output voltage as compared to the input voltage. 5 Vdc input side and 12 Vdc output side. Is this correct or have i got this all wrong? 

Question by WWC   |  last reply


How do I use an Arduino to write say 2.1 volts? Hobo dataloggers accept 0-2.5vdc inputs. Arduino outputs PWM.. thanks!? Answered

I'm working with a university and they love their Hobo's and I don't blame them... they're pretty straight forward to use...  I'd like to write to the Hobo... here's the hobo analog inputs: 0 to 2.5 Vdc; 0 to 5 Vdc; 0 to 10 Vdc; 4-20 mA Hobo stats: http://www.onsetcomp.com/products/data-loggers/u12-006 Analog channels: 0 to 2.5 Vdc; 0 to 5 Vdc; 0 to 10 Vdc; 4-20 mA Accuracy (logger only): ± 2 mV ± 2.5% of absolute reading; ± 2 mV ± 1% of reading for logger-powered sensors Resolution: 0.6 mV Sample Rate: 1 second to 18 hours, user selectable Time accuracy: ± 1 minute per month at 25°C (77°F), see Plot A Operating range: -20 to 70°C (-4° to 158°F) Operating temperature: Logging: -20° to 70°C (-4° to 158°F) Launch/readout: 0° to 50°C (32° to 122°F), per USB specification Humidity range: 0 to 95% RH, non-condensing

Question by hydronics   |  last reply


Electronic Box Lock Help!? Answered

OK so I would like to use a solenoid to unlock a box from the inside, problem is the electronic circuit I designed inside the box operates on 3 vdc and as far as I can tell most solenoids operate on a voltage of 6-24 vdc. Is there any way to make a simple driver circuit for a solenoid so it can operate on 3 vdc?  Below is a copy of the box's circuit so far. I would like the solenoid to be in parallel with the "puzzle solved LED."

Question by TXTCLA55   |  last reply


How do I change Low current DC to high current DC?

Suppose I have a high voltage source of DC with fractional milliampere current.  How can I increase the current? I think Watts is fixed with respect to source. So, if there is 12000 Vdc at 1 milliampere (12 Watts??) I should, in theory, be able to get 12 Vdc @ 1 amp. Practicality aside, is this correct? Practicality engaged:  Is 12 Vdc at 1 amp possible, and how?  4 amps???   

Question by Walap42   |  last reply


Help picking DC on/off switches

I'm in the process of trying to build a battery powered trailer mounted speaker system and i've got nearly all the parts now except for power switches. I didn't think i'd have a problem with choosing some but after searching around the vast majority of switches seem to be rated for AC or 12 or 24VDC and the absolute highest DC rating i've found so far is 28V, the problem is that the highest voltage i'm using is a little under 36VDC so where do i find appropriate switches? I've been getting helpful advice about the speaker project from someone on a forum called SpeakerPlans but they seem to think that i'd be fine using an on/off switch rated at 5A 12VDC despite the higher voltage requirements of my amplifier, i'm not very electronics literate but this doesn't make sense to me and i'm a bit worried about pushing too high a voltage through the switch and perhaps causing a fire or something. I would prefer a rotary switch if possible as i used one on my old 12V speaker and i found that it's a lot less likely to catch on clothes and bodies and break or accidentally turn on while the speaker is being manhandled/transported about. I have 2 circuits in my speaker setup, one is the 36V circuit powering the amplifier/speaker and the other is a 12V circuit powering a small mixer to boost the gain and tweak the sound, assuming i can find a switch capable of handling the 36V is it possible to have one switch that could be wired up to turn on both circuits at the same time?

Topic by ambientvoid   |  last reply


Will this work- 220 VDC 4A power supply - Help Reqd.

I need to generate 220V DC rectified from mains with suitable capacitor. I need to load my four micro switches in parallel with 4A load (with each node 1A). Can anybody help me choosing the values of capacitor and the diode for 4A. I've already blown off the Diodes BY127+330mfd which i used to connect earlier with 1A load. This is for testing the contact resistance of a given micro switches.I need to run these tests for a full day. I'd appreciate some immediate help... thanx in advance guys...

Topic by chuppandi   |  last reply


How to create 120 VAC to 90 VDC Power Supply?

I need to create a 90 Volt DC Power Supply using a capacity, toroid and bridge rectifier. I know that with a toroid you have a primary (input) voltage and then you'll conserve power but have a different secondary (output) voltage. I know that if you put say 120 VAC in the primary, the outputs might be, for example, 50 Volts out, which are also AC. I want the voltage to be DC, so I know that I need a bridge rectifier that will boost the voltage by 1.41 because of the AC to DC conversion. However, you also need a big fat capacitor, and I have no idea how to size and select this. Help?

Question by Matt Adams   |  last reply


How to use a 110 VDC motor plugged into my 110 VAC garage outlets? Answered

I need a bigger motor for my micro lathe project and got one off ebay. its the same motor as on my 7x10 mini lathe but I just realized the motor is 110 VDC and I need it to be 110 VAC. so I can just plug it in to the wall outlet... how do I make it so I can just plug it in and go? Is there some type of wiring trick or some adapter I can use? Thanks!

Question by zacker   |  last reply


Resistors for a NPN transistor? Answered

In the circuit diagram(which I've uploaded),I intent to use a NPN transistor(BC 547) as a relay.The 9 VDC is stepped down to 5 VDC by a LM7805 and should be the trigger to the transistor,completing a circuit which needs the 9 VDC.The Collector is given the common negative of both the voltages and the trigger gets the positive 5VDC.I need a bit help to calculate R1 and R2.I had used two random resistors previously but the Load got powered by the 9 VDC even before the trigger was applied to the transistor.I figured out that the problem might be related to the resistors used. (I haven't included the caps used at the terminals of the regulator in the schematic)

Question by Adarsh_tronix   |  last reply


grounding + 24vdc ?

Can someone explain the following, I got 24 VDC power supply (or take 1.5V AA battery) which is connected to 110VAC outlet on the input, potential difference out of the power supply is 24VDC node (+) to node (-) and potential difference of either one to ground is 0V (outlet ground). Now I take wire and ground (+) of the 24 VDC to outlet ground. Questions: 1. Why i am still measuring 24 VDC across (+) and (-) nodes ? If ground (call it whatever common) is 0 v and ground is touching (+) which was prior to shorting it to ground raised in potential by 24 V in relation to (-) that means (-) is zero potential? Or is it + 24VDC and - 24VDC but than potential difference is 48V at the output of the power supply. 2. Does that mean that I raised the potential of the ground to 24V? Probably not Thanks

Question by onaumov   |  last reply


Power Suppy Answered

I need to make a 6.5 vdc - 500ma power supply I have no clue how to make it 6.5v. any help is deeply appreciated

Question by BluTiger   |  last reply


Looking for relay

I have been looking for a relay that will switch with .3 vdc.  The other side is just a 9vdc source but the trigger has to be .3vdc or lower. thanks

Topic by zuben   |  last reply


Peltier thermoelectric heat pump, can it be used as Solar Generator?.

Can a 40 mm square Peltier thermoelectric heat pump be used as a solar generator It operates on 13 Vdc @ 5 Amps. Operating at 13 Vdc, we measured the hot side at 190 Deg. F and the cold side at 55 Deg F. I have a 6 foot reflector dish and can add Reok led tracker. How many watts will it generate if it does?. Thanks for your help

Question by talei1   |  last reply



Can you tell me the meaning of the abbreviation in this PlayStation controller ? Answered

My friend gave me this controller I'm trying to fix it but I don't know the meaning of these abbreviations, all i know is ACK = Acknowledge CLK = Clock and the Positive and Ground connection. I already searched for the color coding of the wires and try to guest it but still no luck. In case of you cant see the image clearly here are the abbreviations DO,OI,CLK,ACK,CS,Gnd,+3.7 and VDD or VDC im not sure about the VDD or VDC.

Question by RYM3U4JTJDFKZXHPLZTKAR   |  last reply


Did I choose the right relay? Answered

I am building a circuit in which a photoresistor triggers a relay which then powers a motor. The motor runs on a max of .75 amps and uses 4.5 VDC, while the photoresistor side must use a max of a few milliamps and can use anywhere from 1.5-6 VDC. This is the relay I am thinking of: http://search.digikey.com/us/en/products/TXS2-L-12V/255-1898-ND/650137 . I am pretty sure it's the right one, but I wanted to make sure. Is this the right relay for my purposes, and if not, what's wrong with it?

Question by seraine   |  last reply


How can I use a bridge rectifier to convert 120 AC to 12VDC?

I'm using a 12 VDC power antenna to run an automatic coop door opener. 

Question by devlp   |  last reply


Home made charger for a cordless. screwdriver.?How do i connect 2wire charger to 3 prongs on batt.

Blk & dec vpx 7 vdc cordless screwdriver.Missing charger,not available anymore.Batt. has 3 prongs for charger.

Question by    |  last reply


URGENT!!!Reply fast!!!BC 547 switching? Answered

My school exhibition's tomorrow and I need to do something urgent.There's a 7 VDC supply which is converted to 5 VDC by a voltage regulator(both have a common negative terminal).I need a BC 547 to act as a switch and complete the circuit of a device connected to the 7 volt circuit when the 5 volts is used as a signal and sent to the transistor.To put it in another way-The device needs to run on 7 volts when a 5 volt signal is sent to the BC547.I've got about 4 hours of time before I go to sleep(actually forced to!)and the exhibition's tomorrow morning!!!

Question by Adarsh_tronix   |  last reply


Voltage help

Hello I am new to electronics I am having trouble designing a circuit that lowers VDC as ground resistance increases and raises as ground decreases every circuit I've built works backwards. I am working with 5vdc any help would be much appreciated thanks

Topic by Ed69   |  last reply


What kind of SCR would I need for a coilgun with 2500uf 500vdc capacitors? Answered

Using a bank of 6 capacitors, all rated for 500 WVDC and 2500 uF. I'm only going to be mainly using them with 240 and 130 VDC. Would a 500Amp SCR be applicable?

Question by Mudbud   |  last reply


How to convert 120VAC to 90VDC @ .5amps?

Hello, I'm looking for a circuit the will convert 120VAC to about 90 VDC at .5 amps. If anyone could suggest a schematic or point me in the right direction of one that would much appreciated!

Topic by bigjohn412   |  last reply


Potentiometer to control DC motor speed

I have a 12 volt fan in my RV. It has a 1.6 amp DC motor. Would a 2 watt, 350 ohm potentiometer be suitable to use as a variable speed control? If not, what potentiometer would I need?

Question by gaugeguy   |  last reply


Can I use a electric scooter motor for a wind turbine generator?

I'm asking this as that I have 15-20 electric scooters with several different motors in them. I would love to be able to take one the 200-300 watt VDC motors and use it in a wind turbine. thanks.

Topic by jeepinjoe5150   |  last reply


Slowing down an electric motor? Answered

I am on radio shacks website looking at a 1.5-3VCD hobby motor.   The specs say up to 8,300 RPM at no load.   If I added resistors to this, would it slow it down?  I want it very slow, like 1 rotation every 3 seconds. lol   Thanks

Question by pennsteve   |  last reply


i need to use my 60w 127 vac sodering iron in my car as in 12 vdc so i need a cheap easy to make inverter any ideas?

Later i would also like a inverter that could handle a 950W 127VAC angle grinder also cheap and easy (ish) to make

Question by cassiorichiniti   |  last reply


Need help designing actuator system for display bottles in a table

Need help designing actuator system for display bottles in a table.I will need 12 VDC actuators with limit switches, power supply etc.Ultimately i would like it to be activated from a click on a iPad image but not a must.Any help would be compensated for.I am in Toronto Canada

Question by dnicol1   |  last reply


What is the best way to power an LED strip? Answered

I am looking into purchasing some LED strips for a project, but I don't know how to power the LED strip.  For example: This LED Strip needs 24 VDC, but what would be the best way to supply this?  Would I use an outlet?  Are there batteries for this type of thing? Thanks for your help.

Question by Brennn10   |  last reply


How do I power my 50 red 3-watt LED's and my 20 blue 3-watt LED's without using resistors to make a panel?? PLEASE HELP

I am no electrician and am having no luck searching the internet on how to power the LEDs. I am trying to build a grow light with 50 - 3 watt Red LED lights and 20 - 3 watt BLUE LED lights. The total power consumed would be 210 watts. Specs for Blue lights: DC Forward Voltage (VF): 3.2 Vdc ~ 4.0 Vdc DC Forward Current (IF): Typ 650mA Specs for Red lights: DC Forward Voltage (VF): 2.0 ~ 2.8 Vdc DC Forward Current (IF): Typ 650mA I know a lot of things on the internet call for resistors but for this project, resistors would give off far too much heat. I know that an LED driver can be used in place of the resistors, but I don't know anything about voltage or amps. I have found a few 200W LED drivers that connect to an outlet and convert the power to a 24V DC, which is usable by LED's. I just don't know if that's all I have to do: connect the driver to the LEDs in a parallel circuit. Actually, I don't know how to find the Constant Current Module that I need at all. PLEASE HELP ME!

Question by ammakrom   |  last reply


56_0_56VDC = 112VDC Answered

Hi, Just say a 500watt RMS Mosfet mono amplifier the maximum input VDC is rated at 56_0_56VDC, when we test with a multimeter the +56v and -56v voltage is 112VDC, so i am wondering does the amplifier uses the entire 112VDC or it splits the voltage into two 56_0_56VDC because if the amplifier uses the entire 112VDC then i think the 112VDC is a lot of voltage and could burn the amplifier. Thank you.

Question by Lima79   |  last reply


Which diagram would work best(want leds to work at their max potential, Help? Answered

Specs on all 3 leds  1 watt, red green blue Maximum forward voltage: 4 Vdc Maximum forward current: 350/ 700 mA (if you pick a diagram with a resistor please let me know what rating Ty)

Question by dougiedougworld   |  last reply


Could i replace this 555 in this circuit with an arduino?

Http://www.aaroncake.net/circuits/flampdrv.gif In this could i replace the 55 timer this with a arduino? If so what would the code be? If not could you atleast tell me what kind of wave the 555 is producing so that i can emulate the same with an arduino? The circuit in question is for a 12 VDC flourocent lamp driver Thanks

Question by qwerty156   |  last reply


50 Watt LED Wired To DC/DC Converter

Hello, I want to wire a 50 watt led to run off of 12 volts.                                                                                                                                   here is info on components:                                                                                                                                                                                    50 watt led                                                                                                                                                                                                           forward voltage:30-36 Vdc                                                                                                                                                                                  forward current: 1750-3000mA                                                                                                                                                                                                                            DC/DC converter:                                                                                                                                                                                                  input volts: 12DC                                                                                                                                                                                                      output volts: 48DC                                                                                                                                                                                              output current:3A                                                                                                                                                                                                Can I use resistors to make this work?                                                    

Topic by flatfish   |  last reply


How do i make these leds dance to music? Answered

I want to hook the three led's i have up to my PC sound jack, i have parts, i may need more, but my question is how do i hook them up? please leave comments and or diagrams thank you What I have (for now) 3 Leds: 1 WATT ULTRA BRIGHT LED GREEN 45/ 73 Lumens @ 350/ 700 mA 100 degree viewing angle Maximum forward voltage: 4 Vdc Maximum forward current: 350/ 700 mA 1 WATT ULTRA BRIGHT LED BLUE 19/ 31 Lumens @ 350/ 700 mA 100 degree viewing angle Maximum forward voltage: 4 Vdc Maximum forward current: 350/ 700 mA 1 WATT ULTRA BRIGHT LED RED 34/ 55 Lumens @ 350/ 700 mA 100 degree viewing angle Maximum forward voltage: 4 Vdc Maximum forward current: 350/ 700 mA   TIP31 80V TO-220 Transistor (is this the correct one?) i have 3 i also have 24g hook up wire, 3.5 splitter, 3.5 cable with plugs, many battery options as well as wall adapters OK do i have what i need, do i need resistors, what ohm rating, and watt rating, what volt source?  i dont need it to be portable, will be on desk, a wall power supply would be best, please try to make me a diagram with parts i have, but if more are needed i have plenty of resistors to choose from Ty. and a store right down road :) https://www.instructables.com/answers/I-need-a-diagram-please-from-a-knowledgeable-pers/

Question by dougiedougworld   |  last reply


How do I use the LM3914H bargraph voltmeter circuit to switch 2 amp, 12 VDC loads instead of LED's?

I'm thinking either power transistors or relays instead of the LED's, but designing the actual circuit is a little beyond me. I'd actually like to build two of these and use the second to measure DC current of 0 - 20 amps, I'm thinking measuring the voltage drop across a shunt resistor...

Question by stevekrawcheck   |  last reply


Autorange Brymen BM511?

I have an unusual problem. My BM511 will not auto-range and readings on VDC are odd. A 1.5v battery initially shows OL, then 00.61, 001.5 then 0002V as you manually step up through the range of the meter using the 'range' button. I suspect it has been burnt, either the input protection, bridge or scale divider. As I do not have a diagram i cannot fault find. Does anyone have a circuit diagram for the Brymen BM511 DMM. Thanks in advance. Regards, KH

Question by KeithH65   |  last reply


Wall Wart question.....

I have an NCE cx12v500 direct plug in class 2 transformer in the form of a wall wart. I accepts the USA standard of 120 vAC in, at 60 Hz, and outputs 12 vdc @ 0.5 A. I thought this was the recharging unit for my portable drill, and so I plugged it in. After a few hours of charging, the drill moved but was sluggish. I unplugged it, and when I tested the output, it had dropped to around 1 - 1.3 vdc. I can't seem to find a way into the unit either (molded plastic) without sledge hammer or hacksaw usage coming to mind. Did I fry this one I think I did, but I am looking for a possible, no and solution from someone :-) Aaaargh ! I took it apart finally sawed a notch in it and pried it open... and there was #1: NO regulator *sigh*, and #2: NO fuse of ANY kind, and #3: just a tiny board with a 1,000 uF cap on it and 4 diodes (bridge configuration).....one by one I took components off and tested them with my VOMM and sure enough, all the components were good. Then I tested the transformer......and both sides should have tested closed or short, but one side (output) tested OPEN. *sigh* It fried the transformer ! :-(

Topic by Goodhart   |  last reply