Reconn's World Forum

I want to do at the beginning of each hour with a blown LED. Please HELP

guest — Sun, 16 Oct 2011 13:54:42 -0700

Trapped at the beginning of the next hour clock starts at the beginning of another, the different colored LED clock I want to do the burning. hours at 1 to 2 hours, the green LED will light when the green LED will flash red when the red LED will light will go off at 3 to want to make a circuit that will turn blue. Would you please help me to do this?. To now thank you. Sorry ,My English is not good. I did on translation from google
.Me e-mail: emirkutlay@hotmail.com

Re: simple preamp

guest — Sat, 20 Aug 2011 21:03:44 -0700

Hello, I'm building a similar circuit, and am wondering if it matters what kind of capacitors are used, ceramic or tantalum? And if it does matter, could you please explain why?

Thank you in advance,
Vignesh R.

Re: need help finding schematic

guest — Fri, 05 Aug 2011 01:08:17 -0700

"What I achieved were monstrous lumps of solder......"did you use flux?

Re: simple preamp

guest — Fri, 05 Aug 2011 01:04:27 -0700

hi!i am working on a project where i have to take electrical signals from the skin,for a lie detector.the voltage usually varies between 1 and 5 millivolts.so,will this work for that?if not,can you help me with the amp.?

thanks,
Utkarsh.:)

Amplifier Circuit

guest — Mon, 16 May 2011 06:42:33 -0700

Hi
Can anybody help me please? I need an Amplifier circuit (LM741cn) which uses 3 potentiometers as Bass Treble and Volume. I am really struggling to create it. I realised that i can put an alternating resistor in to help with the volume control. And 4 capacitors for the AC. Look forward to replys!!! Thank You

Re: Zapco PS200 DC/DC Converter

guest — Tue, 12 Apr 2011 23:59:01 -0700

good circuit ...its almost working

Voltage comparator help needed for a newbie

guest — Thu, 02 Dec 2010 02:23:48 -0800

Here's my idea/plan. I want to take a wideband air fuel monitor that has an analog aux output that's a 0-5 VDC siganl, 0V = 10:1 A/F ratio, 5V = 20:1 A/F ratio. I want to come up with a Comparator circuit that accurate to the .01V range that I can preset a trigger point so when the A/F ratio exceeds the set point it will trigger a mosfet or optoisolator that I'll have wired to set of injectors to richen the engine up. I'm an older guy, 50 years old just starting to learn working with electronics. My background is in Diesel Mechanics and Power generation. I have a good grasp on how things work. I tried building one with a LM-339 and could not get it to work at the lower voltage range. Somewhere along the way I think I "overloaded" the IC and smoked something, so I figured I'd ask someone that knew more about this than I. This is going on a carburated engine in a 1970 Buick electra 225 with a turbocharged engine.

Re: sound detector tone decoder

guest — Tue, 12 Oct 2010 13:57:42 -0700

I build the amp and tone decoder. I put an LED protected by a resistor on the output of the 567. It lights up as soon as power is applied to the circuit. The only deviations from the plans are the four leads from the electret microphone (mine only has two leads) and I'm supplying about six volts instead of five. What could I be doing wrong?

mic amplifier

guest — Sat, 08 May 2010 12:51:12 -0700

It's simple. A speakerphone telephone when using the speakerphone (telephone mic) the person at the other end always says, "you sound like your speaking into a tunnel," or something like that. It's not the same as speaking into the handset. Is there a way (schematic) I can amplify the speaker mic to make transmission louder?

Phil

Re: Car Battery to AC inverter

guest — Tue, 09 Mar 2010 00:21:11 -0800

Does anyone know how can i get 220VAC with wopping 300W rating from a 12VDC battery B)-

Re: 4 Channel Color Organ

guest — Tue, 01 Dec 2009 19:25:32 -0800

Hello

Nice circuit & just what I have been looking for!

Looks like there is an E1 on the lower right corner...looks like a place a mic input (?)

Re: 12 volt battery monitor

guest — Tue, 13 Oct 2009 10:15:40 -0700

Pls,i want 2 know d circuit diagram for 12volt battery monitor

Re: 555 timer 40khz IR Oscillator

guest — Wed, 26 Aug 2009 20:37:18 -0700

hey...

i just wondering why?? the signal wave at output pin 3 is not a square pulse..instead, i got a straight line with some voltage value...
is it sometin to do with the 555 timer??is it damaged??or might be due to any other reasons???...

plz help...help..sigh..hehe

Re: ultrasonic switch

guest — Sun, 11 Jan 2009 01:21:44 -0800

Hello,

in the circuit's description you write:

Quote

5. Ultrasonic waves are emitted by many natural sources. Therefore, sometimes, the circuit might get falsely triggered, espically when a flip-flop is used with the circuit, and there is no remedy for that.

However, there is a remedy for that, albeit it would require a few additional parts.

First, use a second 555 (or any other oscillating circuit) at a very low frequency of only a some hertz. Let that control the transmitter's 555, so that it will output a pulse train instead of a continuous signal.

Then, use a counter chip, like a CD4017 in the receiver. Instead of feeding the relay driver transistors, feed the counter's clock input. Select an output of the counter to drive the relay driver. Also, add a NPN transistor or N_channel FET between the clock input and GND, connect it's base (or gate) to the selected counter output. This is to make the counter stop once the selected step is reached, despite further incoming pulses.

Finally, add an RC circuit between the op-amp's output and the reset input of the counter so that it resets after a while when no more pulses are incoming. For this to work properly, the impulse on/off ratio needs to be "uneven", that is, not 1:1 (see below).

Doing this, sporadic ultrasonic impulses don't make the relay trigger, as long as the pause between them is bigger than the RC constant on the reset line. If you select, lets say, the 9th output of the 4017, it will switch only after 9 pulses that must come in fast enough.

That's just an rough overview of the addition. Some things depend on the used counter, like the on/off time ratio. Also, depending on the counter, an additional transistor may be needed to inverse the signal, depending on the counter needing a low or a high signal for the reset.

Hope that idea is useful,

Chris

Re: Zapco PS200 DC/DC Converter

guest — Mon, 08 Dec 2008 16:02:53 -0800

I have one of these power moduals. I picked it up at a car boot sale.
The 12 vault in put doesnt seem to be putting out anything, Do you know anything about it?

Mike

Pressure Switch info

guest — Sun, 07 Dec 2008 16:55:03 -0800

Hello,

(Please reply to: phillipv at nb.sympatico.ca)

I need to identify some sort of pressure sensor(s) with which to be placed at specific anatomical read-points along the Exo-frame:

1. Inner wrist for biceps contraction
2. Outer wrist for triceps contraction
3. Mid-biceps for shoulder raise
4. Just above elbow for rear shoulder raise
5. Upper knee for hip raise
6. Rear lower-leg for hip swing back

Need to be able to set a threshold for the sensors for each position�s EoCL (Edge of comfort level). If the threshold is not triggered, the joint remains un-actuated and under the pilot�s power. Or perhaps some variant of this method that proportionately increases the actuator power with the amount of force registered by the sensor. This selective passivity will allow for a greater amount of power conservation and employ more natural stored energy release for things like the Contra-Postal walk that kind of feeds itself energy via the spinal torsions, arm swing and hip swing.

Phillip

Please reply to: phillipv at nb.sympatico.ca

Re: 5 volt power supply

guest — Sat, 06 Sep 2008 18:21:09 -0700

Hey,

I found this site from googling 5v power supplies, I was going to order the parts and didn't find a 4A Bridge rectifier. I went back to check the schematic and in the picture it has a 1A ontop the bridge rectifier. Could someone that build it already or knows off hand, tell me weather i should get a 1amp bridge rectifier instead?

Thanks
~Z
Life_Drained[at]hotmail[dot]com

HELP ME PLSSSS.......

guest — Tue, 19 Aug 2008 05:46:44 -0700

can you kindly help me...

can you give me a schematic diagram for a transistor based power supply AC to DC

output voltage:

2.5
5.5
8
10
12

thx...i need di as soon as possible...

email me at thugsterz_15@yahoo.com

HELP ME PLSSSS......

guest — Tue, 19 Aug 2008 05:43:59 -0700

can you kindly help me...

can you give me a schematic diagram for a transistor based power supply AC to DC

output voltage:

2.5
5.5
8
10
12

thx...i need dis as soon as possible...

email me at thugsterz_15@yahoo.com

HELP ME PLSSSS......

guest — Tue, 19 Aug 2008 05:43:49 -0700

HELP ME PLSSSS.......

guest — Tue, 19 Aug 2008 05:40:43 -0700

TRANSISTOR BASED POWER SUPPLY AC to DC

guest — Tue, 19 Aug 2008 05:39:06 -0700

TRANSISTOR BASED POWER SUPPLY AC to DC

guest — Tue, 19 Aug 2008 05:38:19 -0700

can you kindly help me...

can you give me a schematic diagram for a transistor based power supply AC to DC

output voltage:

2.5
5.5
8
10
12

thx...i need di as soon as possible...

High frequency ring tone detector

guest — Thu, 17 Jul 2008 13:03:12 -0700

I was wondering if anyone had a diagram to build such a device. I need something to ID when such tones are ringing in a classroom.

Re: Stun Gun

guest — Thu, 24 Apr 2008 15:28:48 -0700

If you are looking for full blown diagrams on making a stun gun, you can find them on our site located @ [StingerDefense.com]

We do sell both Stun Guns and Taser, however I do have several diagrams on how to build them located at the link above.

Thanks,
Nate Neel - VP
Stinger Defense
Stun Guns, Pepper Spray, MACE and Tasers
[www.StingerDefense.com]

Re: Stun Gun

guest — Wed, 23 Apr 2008 02:13:23 -0700

guest Wrote:
-------------------------------------------------------
> Here is a Stun Gun Schematic.

Of course, a stungun these days only costs around 20 bucks. And I figure that would be a whole lot better built and reliable...

Have a look here [www.StingerDefense.com]

Re: 555 timer 40khz IR Oscillator

Justin9 — Fri, 22 Feb 2008 20:28:24 -0800

I would like to use this for a project I'm working except I will be using 12 volts instead of 5volts and I have have 8 infrared leds... can someone help me get all the resistors right?

andrew Wrote:
-------------------------------------------------------
> [www.reconnsworld.com]
> 40khzir.jpg
>
> parts:
> U1 555 Timer IC
> R1 47 ohm resistor
> R2 470 ohm resistor
> R3 5k variable resistor
> C1 0.0047uf ceramic capacitor
> LED1,LED2 Infrared LED's
>
>
> This circuit oscillates two infrared LED's at 40
> khz. To make sure it is transmitting IR light, you
> can get a little tool from radio shack for about
> $5. It is a small sheet of plastic about 1" by 3"
> with a special strip of material, that when
> exposed to IR light glows (it's actually kinda
> cool..) A way to check for 40khz IR light is to
> build a circuit that lights an led when 40khz
> light is detected. You can get the schematic by
> clicking here.

A circuit to generate between 16 khz and 20 Khz Ultrasound

pedro — Tue, 22 Jan 2008 15:15:55 -0800

Hi Everyone!

I'm new at this f�rum. I'm not good at electronics, but I like to make some gadgets at home.

I'm trying to find, in the WEB, some circuits to produce 16 Khz Ultrasound. I'm planning to make a gadget with it.

I, only, found a circuit to produce 40 to 50 Khz Ultrasound, but I think it is very high for my project.

Can anyone help to find it?

Thanks. Sorry about my english. It isn't very good.

Pedro

what amps RMS

mercy — Thu, 25 Oct 2007 18:36:01 -0700

I am another one of those guys that dont know anything but am trying to find out relevant things. Whan looking at a schemaic, how can you determine what the RMS watts of an amp is?
Thanks

Re: Solar Charger

jimboy123 — Thu, 23 Aug 2007 19:40:11 -0700

can i see the diagram?