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Amps

Can anyone tell me what happens if you take two 1.2v, 1900mAh  rechargeable batteries in parallel connected to an LED?  Does it increase the amount of time the LED will stay on?   I'm new to this.  Working with small solar charging lamps.  Thanks Patty

Topic by PattyCA    |  last reply


How to make 1:1 transformer? Answered

Hello , i want to make a 1:1 transformer for audio (guitar pedal to power amp input).Can i use this size of transformer ? and i want to re-wire it with the type of wire in the image , how many rounds the transformer need? Thanks in advance ! sorry for my bad English!

Question by login721    |  last reply


10W audio amp?

Ok, so i want to get this one audio amp to work, but i can't seem to figure out how to wire it! the first picture is a schematic, and i have NO idea what the connections are, 1, 2, and 3 the second is a picture of the amplifier chip

Topic by Sandisk1duo    |  last reply


Converting Sub Woofer amp to guitar amp?

I have a powered sub-woofer that had a blown speaker and being that I spent the money to get a better one I thought that converting the old sub woofer amp to use for my guitar would be a good idea. I already have something to practice with but making something that can be used for gigs would be great. However, I'm not an avid or experienced electronic wizard and will need the help to complete this project. Here is the info I have on the amp itself; OUTPUT POWER                          50W (4 ohms,DIN) THD                                                  10% @ 55Hz Reproduction Freq. Response   45Hz - 150Hz Phase Switch                                  0, 180 degrees Input Sensitivity (Sub In)                460 mVrms AC Power                                         120V/60Hz            Power Consumption                     70W (at 1/8 rated power) Standby Power Consumption     <6W What I do know that I need is a 1/4" mono plug jack and being that the input for the woofer is mono putting that in shouldn't be a problem. I'm mostly concerned about the frequencies that the amp will handle for playing a guitar and speaker recommendations. Plus any other opinions will be appreciated. I am expecting this to be a clean sounding amp and as it sits will only provide volume. An EQ is planned to be used after this amp is put together and then eventually an overdrive. I'm planning on connecting 2 50W speakers and wondering if I should hook them up in serial or parallel. With the help of my fellow instructabl-ians I will be able to post my 1st submission.

Question by 95sprtcpedrvr    |  last reply


OP-Amp Troubles

Hey everyone I was hoping someone here could help me with a problem in having. I've been tinkering with some op-amp circuits with the LM386N-1 namely the one I have pictured. I first assemble them on my prototyping station and they work well using the signal generator but when I connect them to a audio line from my computer nothing comes out the speaker I have tested the cable and speaker and they both work so I am at a loss as to what's not working. I would appreciate any help you guys can give me thanks

Topic by juggalo_assassin183    |  last reply


can a double a battery pull out 1 amp? Answered

If its rated 2000 mah it should be able to right?>

Question by ismael01    |  last reply


Using L293D Chip for a Single 1 Amp Motor? Answered

The L293D chip outputs only 600ma of current for each channel. Can I combine its two channels to draw a total current of 1.2 A to run a single DC motor that needs 1A current?

Question by raftor    |  last reply


Little Gem Amp Problem

Hi all I am quite new to electronics but I am very interested in it. I have built a couple circuits before but nothing with an IC chip. So now I have decided to move onto slightly more complex projects,  and I found the Little Gem Guitar Amp: http://www.runoffgroove.com/littlegem.html I have built it on a veroboard from these diagrams but I changed the layout slightly. Obviously everything is connected the same way I just moved the 100uF cap a little up. I have also added a 10Ohm resistor to the output and used headphones instead of the speaker. When I connect the 9V battery, without an audio source, I can hear is a soft buzz, quite a high frequency. The gain pot makes the noise louder and softer so I assume the LM386N-1 chip is fine. If I put my finger on the ground part of the 1/4 inch jack, the noise become much loader and lower frequency. The same thing happens if I connect an audio source. Is there an obvious cause for this problem that I don't know about? I have connected the jack to the board with shielded twin core wire. I have used the shield as ground and the core as signal. Is this correct? Any help would be appreciated, I would like to get this working.

Topic by geniass    |  last reply


DIY Ipod Amp Kits

I have all put together all the parts to make your own iPod Amp as seen in ReadyMade magazine issue 23 and Instructables.The kit includes:Velleman Amp kitSpeakerArmy Surplus Case1/8" Stereo JackWireLEDResistorNuts and Bolts to secure speakerPower Switch6AA Battery Holder w/ snap connectorThe price is $45 + $5 for shipping. You can follow the step by step instructions at: https://www.instructables.com/id/Simple-iPod-Amp/Thanks,-JoeYou must pay with paypal and I will only ship to the US, sorry I just end up losing money any other way.

Topic by joe    |  last reply


How to power 8ohm 1 watt speakers?

I'm working on a project for school that consists of a wireless speaker. They will be mono speakers.  I have an 8 ohm 1 watt round speaker. I would like to power these.  I've read on lm386 and tsa7052 ic to do this. For the wireless I was going to use dexdex's instructible bluetooth headset hack I'd like to power it all with a 9volt or a lithium hacked out of old product. Are there any things i should know for the amplifier in relation to the type of speaker i will be using?  Will i be able to power the bluetooth headset and the amplifier from the 9v? thanks for your time!

Question by williamhaze    |  last reply


Portable Guitar Amp Hiss

Hi all, I have built this design with a few modifications to accommodate for the parts that I already have. I used a stereo 1/4 inch stereo jack, but I connected the 2nd signal to the battery negative and the ground to the circuit ground. This way the circuit switches on when I plug in a guitar. I also used headphones only instead of a speaker, so I don't need a switch. Now the circuit works and it is amplifying the sound, except there is a very load hiss. I am assuming that a certain frequency in not being filtered out but this may not matter when using a medium quality speaker because of its low frequency range. However high quality earphones can play this sound. Is this correct? Does the headphone work for anyone with the hiss? Thanks in advance

Topic by geniass  


Is Lm386L is the same LM386 or LM386N-1? Answered

Are these the same, from the datasheet it looks identical to the LM386N-1 and I read the L is just a certain manufacturers way of saying it is lead free. So does anybody know if they are the same and if so which it is comparable to? I.e just the 386 or the N-1, N-2...etc. Can I use this directly in the same circuits as LM386N-1s.. I can't see why not from looking at the datasheets. datasheet for the 'L' chip http://www.datasheetdir.com/LM386L-D08-T+download LM386N-1 datasheet: http://pdf1.alldatasheet.com/datasheet-pdf/view/8890/NSC/LM386N-1.html

Question by mdog93    |  last reply


Can I use an IR receiver for a low voltage application (1 1/2 - 4 volts) - (1- 2 amps)?

I found one with the proper voltage but is .6 mAmps

Question by undersea    |  last reply


need help with lm386 amp? Answered

Hello , i making a little amp.This is the layout: I use a AC to DC adapter (output DC 9V 200mA) as the power source, 8ohm speaker( the sharp 939 speaker).My stratocaster or mp3 player as the input. I have some problem with it : 1.I want to add a volume control , but i don't know what volume control should i use (resistor value) and where to put it (before the cap 220uF or after the cap)? 2.I want to add a gain control(for distortion effect), but some people use capacitor, some people use resistor.What should i use ? 3.When i plug in my Guitar, the speaker starting to noise, but when i touch the guitar string,a metallic or  the GND line, the noise disappear.How can i slove this problem ?? 4.What the pin7(bypass) of the LM386 use for and how can i use it ?? Thank for advance! Sorry for my bad English. :(

Question by login721    |  last reply


How do you raise the current from 1 amp to 2 amps without changing the voltage?

How do you raise the current from 1 amp to 2 amps without changing the voltage

Question by DELETED_MakerNinja    |  last reply


How to use an op-amp?

Hi, I've got an op-amp, the part number is OP07CP and I am trying to use it to amplify a voltage by around about 200 times. My set up is 6v going into a voltage divider with one resistor of 100ohm and a variable resistor of 10,000-50,000 ohm, so the output is 10mV-50mv. What I want to do is have the op-amp proportionally increase the voltage, so it goes to a voltage range of 1-5v, which an arduino can read. The power supply is  5v (from the arduino) and the powers both the voltage divider and the op-amp. For some reason, following the simple non-inverting op-amp configuration I just can't get it to work. Do I need a separate power source for the amp? I think it might have something to do with the fact that the amp's ground, input and negative are all just going to the arduino's ground. What can I do to fix it? If someone could help or even give me exact values and configurations of components that would be fantastic. I know that the amp and divider seem like a pointless complication if was just trying to measure the output of the variable resistor, but if you knew the greater extent of my project it would make more sense. Cheers

Question by makincoolstuff    |  last reply


more powerful, portable amp

I was messing around with some op-amps, building variations of the CMoy amp, etc. But I became depressed quickly -- these ICs' data sheets say that at the safe maximum of 15 volts, they can only pump out around 1/4 watt of power on a single channel! Well, i have a full range driver that really needs more power to sound decent. I was wondering what the normal way of constructing an amp would be if I were looking for 5 to 10 watts of power. *edit*: i'm not looking to run this thing off of batteries... i'm sure at 10 watts, a couple of D cells would get drained rather quickly... I recently cracked open an old 4.1 computer sound system (by microlabs) and scrapped the 5 drivers (4 satellites and a 5 inch sub), two big 3700 uF caps, and two JRC4558D dual op-amp ICs from the amplifier. I read up on the JRC chip (actually, just the data sheet from the RC5448D, the texas instruments flavor, i guess the JRC is discontinued) and it seems that this thing only puts out a max of 200 mW per channel, and typically around 90 mW. Ok i know those speakers didn't get THAT loud without distortion, but i am CERTAIN it was more than 800 mW for those 4 satellites. I am a new computer engineering student, so i can understand the physics behind the electronics, but i am nowhere near the level to start reverse-engineering that amp board. So how did these speakers get driven so hard? THANKS for reading!!!!!

Topic by samurai1200    |  last reply


Relationship between volts and amps

I'm working on a project found in this thread https://www.instructables.com/community/Solar-powered-cell-phone-charger-case-hack/ I think I'm almost ready to buy parts and start building but I have a small issue with getting the exact voltage and amperage output I need. I've been researching for hours and I can't find a simple answer to this problem. As I understand it, as voltage decreases, amperage increases to compensate and maintain wattage. Working on this basic understanding I've come up with this model. If I have a solar array consisting of 6 PV cells (1.5V 50mA ea) wired together I get 9V and 300mA. This is too much voltage and is on the low end of amps I want. If my math (and understanding of the subject) is correct, then if I use a 5V voltage regulator I will have a final max output of 5V and 433.3 mA which is right about perfect. Am I doing this right or is there more to it, like how I'm wiring the cells together? Am I correct in the idea that using a voltage regulator will increase my amp output? I'm not schooled in electricity in any way so I would appreciate any help I can get on this in as simple of a form as possible. Everything here I've put together from several hours of studying sites on solar DYI and electricity. Thanks. For reference, these are the solar cells I was referring to: http://cgi.ebay.com/High-Efficiency-Solar-Cell-32-22mm-1-5V-50mA-0-075W-/320541888508?cmd=ViewItem&pt;=LH_DefaultDomain_0&hash;=item4aa1c90ffc#ht_2428wt_1148 *EDIT* Below is a diagram of what I suspect may give me a 5V/490mAh output which would be absolutely perfect. I need to know if I can wire two different sizes of solar cells together in this manner and how it will effect the output.

Topic by HittingSmoke    |  last reply


Subwoofer output from my creative card??

Hey guys, can someone help me with this?? I have one of these sound cards, as you can see in the picture. It's worked pretty good for me for the past couple of years, but usually the subwoofer output comes either straight from the normal 2 channel stereo output on the card, piggybacked onto the cable that goes to my stereo and then that goes to my sub amp. Either that or right now I have the subwoofer amp hooked up to the line-level subwoofer output on my surround reciever, but it's still 2 channel audio. I've recently been fiddling around with my sound card, attempting to get the subwoofer output on it working. I've tried the black socket on the sound card with a 2 channel 3.5mm to RCA cord and apparently it's the rear channels as the subwoofer volume slider didn't do anything in my creative control panel, and according to a pdf I found online for my sound card, the S/PDIF socket also functions as the center/subwoofer outputs when not being used for S/PDIF. I've tried a 2 channel and also a "3 ring" 3.5mm cable I have for a camcorder (As I believe some of the cables that are SUPPOSED to go with this card, have 3 ring contacts on SOME of the cables). Alas, all I've been able to do is get a loud humming sound out of the connections, doesn't matter what rca channel the subwoofer is plugged into, it hums VERY loudly and absolutely no sound what-so-ever. Does ANYONE have any clue as to what I do to get subwoofer output from the card?!? Heres a link to the PDF describing what each port is for under "Creative Sound Blaster Live! Digital Entertainment 5.1 Creative Audio Software" and then the submenu "Installing sound blaster Live@ Player 5.1" and the next submenu "Connecting Related Peripherals" and that page describes what each port is for. files2.europe.creative.com/manualdn/Manuals/TSD/790/English.pdf

Topic by Punkguyta    |  last reply


Can someone help me with a simple audio amplifier?

I need to build a simple audio amplifier for an mp3 device for my A levels, but i dont know which amplifier to use, i would like the amplifier to have a variable gain of zero to the maximum and i also have 2 0.5 watt 8 ohm speakers. I was going to use the simple amp from here, but i am not sure if i can get the full 1 watt from the speakers using that amplifier. Any help will be appreciated.

Question by COOL_Q    |  last reply


How to make a 1-1.5 volt voltage regulator at 15 amps?

Hi, I want to make a high current (15 or 16 amp) voltage regulator that outputs around 1 to 1.5 volts. Does anyone know how this could be done cheaply and easily? I've looked at the 15 amp schematic in the LM338 datasheet (http://www.ti.com/lit/ds/symlink/lm138.pdf  page 11), which uses 3 LM338s in parallel, but I'm pretty sure that takes the minimum output voltage to about 4v, way too much for me. I've looked at using 2n3055 transistor, but it seems like I'd need ridiculous heatsinking and probably fans to avoid thermalling out. I'm thinking of taking my power from an old PSU, 5 v rails, so not too much of a voltage drop, but it's hard to find stuff that can handle these kind of currents. I'm pretty much stumped right now, anyone got any ideas?

Topic by lolkent    |  last reply


Salvaged smd micro controlers.

Hello everyone, i just salvaged some great finds i think i have a surface mount PIC16F72-1/SO and a PIC16F877A, plus a few other componets. i am wondering what do i need to be able to program and use these PIC's i have very limited knowledge on micro controlers, i am currently learning with the Arduino UNO. and help would be appreciated. and also i have salvaged some other parts kia324f "quad amp" will this work like the more commonly used op amp's i see in other instructables, ATMEL346 not sure what i can use this for. i have more parts that i am unsure of what if anything i can use them for but i dont want to bother everyone with my list =) ill try and post them a little at a time. and agian thank you in advance for your information.

Topic by omnacron    |  last reply


Do I need a voltage regulator in this circuit?

Hi, I am trying to build a portable usb charger the outputs 5V when input is 1.5 or 3 Volts. I found this step up converter: goo.gl/RAV9dC The spec for the converter state that the input voltage is 1V to 10V, and the out put Voltage is -1.5V to -10V and 3V to 10V. I frankly don't know how to interpret this information. It seems to me that by inputting 1.5V, the output will be 10V. So I am wondering if am right, and IF I am, then do I need to put in a 5V voltage regulator in the circuit? Thanks!

Topic by syedj94    |  last reply


rgb led and 1 analog input? Answered

Im trying to make an rgb led light up in different colors to based on the analog input, for instance a "potentiometer" or equivelent like the lm324 controlling the input causes the input to go higher the red turns on then green and then blue progressively, i have some code worked up but am willing to work from scratch again, im working with the lm324 op-amp and an arduino w/328

Question by redd.the.cat    |  last reply


How to change old speakers into amp.

Help! I've got a pair of JVC 5-way speakers that I'm trying to power with a Danelectro E-studio 9V headphone amp for my guitar. I've been successful using it to power some old walkman type two way speakers by just plugging into the headphone port. The JVC's will take up to 400 watts. I made a small port 1/8 plug but to no avail. Any ideas?

Question    |  last reply


What's up with Amps, voltage and current?

So I'm having trouble finding out where amps come in. Typical batteries (AAA,AA,9v,3v) don't say the output amps, just output voltage. But things like RC batteries, and wall transformers have a specific amperage output. So say my LED and 9v battery. I know I need to use a 150 ohm resistor. Since resistors limit current, then is there still 9v going to my LED its just the amps/current that being lowered before going into the LED? If resistors limit current, or in its unit of measure, amps, then my LED is still getting the supplied voltage just a lowered amperage?  How do I know how many amps my projects are drawing? How will I know if my DC wall transformer with 12vDC and 1 ma isn't going to fry my circuit? How would I know if 1 amp is too much or not enough for any my circuit? Please help, none of this makes sense, ~electricloser  

Topic by HavocRC    |  last reply


What amp would fit these speakers?

I'm looking to buy an amp to hook some speakers up to but I don't know the specifics of what I should be looking for. I'd like to get it from a store and know what to get ahead of time. The speakers are two combo woofers/tweeters and rated at 200w peak power and 4ohms. How many watts should the amp be? The amp needs to take bare red/black water, have a 3.5mm line in, and plug into the wall. This isn't going to be part of a big home theater system, just a little unit so what would be a good cost of a low end amp? Thanks for the help.

Topic by Ronmarru  


ammo can speaker amp problem

I have a 5v amplifier to a set of speakers mounted in an ammo can. usually it works fine but when i plug the audio jack into my phone(s) it sounds like there is no amp, very quiet. the cord has 2 micro usb outputs (meant for two amps but i only have 1) a audio jack, and a usb plug for charging. the sound works fine when i plug the usb and audio jack into my laptop but just the audio jack into my phone doesnt work. the power comes from a rechargeable battery connected onto the amp. if i was unclear about anything please tell me

Question by fossilshark    |  last reply


8 Watt Guitar Amp Help

I've been fartin around with electric and acoustic guitars for about the past 5 years. Only now am i getting decent (by no means good, but better, i guess...). I've been wanting to make a small amp with a small speaker for some time now.I saw this circuit the other day. Its VERY simple.http://www.aaroncake.net/circuits/amp.aspIt says to reverse the values of R1 and R3 for use as a guitar amp. there's some other stuff too. I was going to see if i could pick the stuff up at radioshack tomorrow, and maybe make it an after-work project for the week. Maybe cut up some wood and make a nice box for it. 1)Do you think these parts would be available at radioshack? and what do i need to look for if i cant find the exact IC? 2)Any special soldering tips? 3)What kind of pot do i need to add, and where, for a volume knob?4)Is there any extra things you think that needs to be added?5)Are those triangle things grounds? as in 12v negative? And what about the other wire from the guitar? 6)Also, what ohmage speaker do i need to use? What am i looking for in a speaker?7)Will 8 AA batteries do the job?8)Do i need to add like a fuse or something somewhere? Going straight into the IC...i dont know. If anyone knows of simpler or better designs, let me know. I seem to really [insert proper four-letter word here] up electronic things. I think thats all the questions i have here. To respond you can just go like..1)i think that....like that. Hopefully that will make it easier to answer all my ignorant questions.Thank you!Jason(sorry if i seem like a a$$ here. Its 1:35am, I've been looking this stuff up for two hours, and i dont feel like i got any further....)And since i dont have a suitable picture, have yourself a look at my LEGO steam engine: (after the third try of trying to post the video with unsuccessful results, i realized that i was posting the embed code int eh URL place...need....sleep....)

Topic by John Smith    |  last reply


this bloody amp is going to get bined if i cant sort it out?

The relay in side has switched on to protect the speaker and wont switch back so there must be a fault some where can`t find 1 though..... errrr  not getting any readings via a multimeter on circuit board and i need a servicing manual to know where to prob  any help...

Question by andybuda    |  last reply


How to make a battery powered 5.1 speaker system?

Hi, I was wondering how I would be able to make reasonably powerful MP3 speaker system which is battery operated has 5 speakers( two tweeters, two mid range and one sub)? What sort of amp, circuitry and parts would I need? I was thinking about using amps like these...http://www.kemo-electronic.com/en/module/m032s/index.htmhttp://www.maplin.co.uk/Module.aspx?TabID=1&ModuleNo;=46809&doy;=24m7Thanks.

Question    |  last reply


Is there a way to lower a photocell's resistance to amps? Answered

I am making a device which uses a laser to lower a photocell's resistance to the point where enough current can flow to begin spinning a motor. Unfortunately, the motor (4.5 V) starts off by drawing about .75 amps and once running falls to .25 amps, but apparently the photocell can only draw a lot less- the only word I've been able to find is that it typically draws about 1 milliamp, which is nowhere near enough. I have two questions- first off, does anyone know how many milliamps I can run through a photocell, and is there any way that is pretty cheap so that I can lower the amps drawn or the resistance of the photocell without stopping the motors?

Question by seraine    |  last reply


12v timer to run a 12v dehumidifier for a few hours per day

I have a 80 w  solar panel on my caravan, wired to a 12 v leisure battery 110 amp. my question is how do I get  a 12 v  dehumidifier  to run for 2 or 3  hours per day on a timer.  unable to run continuous as not enough solar power yet as it is still winter. I have a basic knowledge  in electronics. I have not got 240 v available any help would be welcome   thanks in anticipation.  

Question by cossiem    |  last reply


The Iphone 3gs uses upto 1 amp while charging , what if i use my 2.2 amp battery?

If i connect it to a spare 2.2 amp battery i have will it use as much amps as it can ( 1.0 or 2.2?) or will it just charge for 2.2 hours at 1 amp per hour?

Question by tylak    |  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


Circuit to connect stereo output to 5.1 speaker system?

Hi all! I am after a circuit that will mix a stereo source together (into mono) then pipe it out to a 5.1 speaker system. Obviously the simple solution is to wire the left and rights together and then patch into each speaker on the 5.1 speaker system. However it causes noise and other audio artifacts. I am thinking some form of op-amp type circuit to mix the L and R. That then either can be directly split between the speakers or goes into another pre-amp circuit for each speaker output (maybe even a band-pass for the sub woofer). Just to explain what this is for: I want to have music in a workshop. At the moment we have a standard radio which, to be heard the other side of the 'shop, is quite loud. Those near it then turn it down and arguments start (not quite but you get the idea!). I want to use my old 5.1 computer speaker system to spread the sound around the 'shop evenly so the volume is constant no matter where you are - a poor mans PA system.

Question by smartroad    |  last reply




can I run a 1 ohm stable amp with 4ohm subs wired to 2 ohms ?

I have a Hifonics Zeus 3216 and 2 sundown sa12 d4s. the amp is a 1ohm stable so can I use it to push them safely?

Question by NathanH163    |  last reply


Putting a 1/4in Stereo Jack into a computer :)

I'm thinking this will be my first instructable. I plan to put a 1/4 in stereo jack in the front panel of my PC. I can do that. The problem is, I need to figure out a way to amplify the sound, since my 30-year old earmuffs use a 1/4 inch jack and suffer from low power. I'm thinking USB power. Any suggestions? I know comps, I know how to do this, I just know nothing about amps :)

Topic by mikesty    |  last reply


Help Wiring my AMP for Homemade Speakers?!

Hi guys, please take a look at the image below and try to answer these questions for me please, it will be greatly appreciated and you will be mentioned in the credits of my final instructable when its made. 1. How many Watts Per Channel is it? 2. What does it mean by A+B? ie. Does it mean connecting 4 speakers? 3. Could I wire a Subwoofer crossing over the Right + to Left - Terminals? Finally, I'm going to have a 10" Sub with two tweeters wired up. Should I wire each tweeter to Left and right? Im also going to wire in an L-Pad for the Sub. Thanks a lot guys!

Topic by wizzywoo    |  last reply


Can you splice audio cables into the back of a receiver?

Hey all, I have a 5.1 sound system hooked up to my computer's sound card. The front, rear and sub each have separate amps. However, I am not running a center speaker. (ie. quadraphonic with sub. or 4.1) I am wondering if it would work to route the center output into the amp for the front speakers. i would simply splice the wires so that both center and front signals went into the same connector on the back of the amp? What I am wondering is if doing this could mess up my sound card.

Question by brendanvista    |  last reply


Can I use 741 op amps instead of 1 LM324 in a heart rate sensor?

Http://makezine.com/video/visualize-your-heartbeat-with-this-homemade-pulse-sensor/

Question by DangerousTim    |  last reply


can someone help me put an output jack on my guitar amp? and help with my amp stand?

So im building a guitar amp stand made of wood. my future plans are to put up to 4 12-15" speakers in the stand. i dont have the speakers yet but i plan on getting them soon so i need a way to put an output jack on my amps. I had plans to simply attatch a 1/4" jack to the leads from the amp speaker but I now have second thoughts about this because of the fear of doing damage to them (i had the same problem with my computer speakers and I blew out the amp) so how else could this be done? amp 1 -- -guitar amp -19W -transister amp 2 -- -bass amp -35W -transister i dont know if this information helps at all i also want 3 separate channels 1 for each amp (i might possibly get another amp so i want to be prepared) if one is a bass and the other a guitar amp do i need bass speakers or will any do for the Bass i want to control the volume of each channel separately so i will need to know what kind of potentiometer to get and i want the sound to be decent if one amp is not in use at the time basicly i want the stand to act like a high proformance cabnet with volume control and separte channels can this be done? Ive drawn a design is the wireing correct or can it be beter

Question by fastcar123    |  last reply


How do i make a 1 amp boost converter that converts between 3-5v to 5v?

Hey, so  have been buying pre built boost converters but i wanted to build my own, my question is, how can i make a step up boost coverer circuit that takes between 3 and 5 volts and converts it to 5 volts at 1 amp. In you answer could you explain what each part does? Thank you!!!

Question by jbdawinna    |  last reply


If i make 5 LM1875 circuits, and put them in series, will i have 100 watts output power? Answered

What i mean is can i set it up like: audio source> input amp 1> output amp 1> input amp 2> output amp 2, etc... will there be around 100 watts ant the output of amp 5? Also can i use the same power supply for all 5 and put the voltage inputs in parallel? (i.e. the 5 Vcc's in parallel with the positive output from the power supply, 5 Vee's in parallel with the neg of the power supply) heres the national semi page for it: http://www.national.com/mpf/LM/LM1875.htmlif for some reason this doesnt work, can someone link me to a ~100w solid state amp, preferably something simple like the lm1875

Question by tigerdog330    |  last reply


need some help with making an amp for speakers

I have a speaker that looks like the ones in the image but it has bigger magnets. its a 3Watt and 4 Ohms. i have another speaker but its only a 1.5 watt and i can't remember the ohms i think 3 Ohms. i wanted the 3watt speaker to be a little subwoofer in a little box that i am making but i don't know how to make an amplifier that can make one play regular and the other one just bass. if you have one i can buy it off of you if you will let me. get some info how to make an amp of you can sell me one and witch one i connect it to and i plan on using a   9 volt battery. the 3 Watt speaker came from a KAIDEAR portable speaker. these speakers are how the kaidear speakers look but with a big magnet and i only have 1 speaker for a little sub and a t.v. speaker for regular audio.

Question by Ziggy Jones    |  last reply


LM386N-1 Guitar amp- get feedback/radio hum/crackle when run off AC/DC power converter...? Answered

Hi Last year I built a mini guitar amp using the LM386N-1 IC and I followed these instructions/ schematic and modified it a little with the help of the author. https://www.instructables.com/id/Make-a-Sweet-Portable-Guitar-Amp/ I integrated a switched DC plug so that I can run it from a 9V wall supply. When I use it with the wall wart I get a radio hum and crackle feedback that I do not get from the batteries. Is this because of the type of transformer? I've read something about audio grade power supplies before but cannot remember the ins and outs. Does anyone have any insight into the cause of this humming? Thanks

Question by mdog93    |  last reply


Splitting a power supply 3 ways? Answered

Is there a way to split a power supply 3 ways? power supply is going to be around 12v  6A, needs to be split between (2) 2.5 amp speaker amplifiers, and (1) 5v, 1a (or 500ma) ipod charger. Just wondering so i dont have to buy 3 plugs :)

Question by astroboy907    |  last reply


50 watt electric and bass guitar amp?

Good day to all, i'm new to this site hope i can gain more knowledge in electronics here, since i have been doing alot of programming lately.. i am planning to build my first higher wattage amplifier for both guitar and bass, i already have built smokey amp and its other cousins like the ruby amp and some guitar effects. i will build the two amps simultaneously and put  it in one housing.. the speakers will be separated and also the circuits and all.. does any one have schematics for this kind of amplifiers?? it should bea solid state amplifier, because its hard to find tubes here and also it is expensive.. correct me if i'm wrong 1. "instrument >>>preamp>>>poweramp>>>>speaker" ? 2. is it possible for example to use a smokey amp as the preamp section and connect it to a 50 watt power amp? 3. what type of speaker should i use for the guitar and for the bass? should it be a woofer or sub-woofer? coz i dont have a clue on speakers.. tanx in advance..

Question by VAustin89    |  last reply