wireless LED circuit design

[steev]

hi all
iam trying to design a simple wireless circuit which can drive 3-5 brigh LEDs.
after a lot of search i found this circuit http://www.aaroncake.net/circuits/irremote.htm it looks simple and very compact. but as i want to drive 3-5 LED's how much power i have to use and what components do i have to modify.

and the operation shld be like LED's glow when i press the transmitter button and go off when i release it.
pls help me in building it
thanks

[audioguru]

Hi Steve,
Welcome to our forum. ;D
That faulty project is also on our site:
http://www.electronics-lab.com/projects/motor_light/030/index.html
It won't work properly unless a resistor is added from pin 3 of the opamp to 0V, as its reference DC voltage. Use 100k to 1M.

The old LM308 opamp isn't made inexpensively anymore. Use a much better, modern and cheaper TL071 or TL081, then don't use C3.

Why use a relay when the LM567 can easily drive 5 LEDs?
Tell us the typical voltage of your LEDs and what kind of battery you are using and we will show you how to connect them.

[steev]

amazing.thanks for ur fast reply.
now i'll explain u in detail.as i said i want to drive 4 normal bright LED's remotely.
requirement:-and the ckt(receiver)shld be such that it will drive 4 normal bright LED's. when i press the transmitter button and go off when i release it. i know remote operation can be done using either RF or IR. i choosed IR as it is easy.

limitations for this ckt is,receiver shld be as small as possible using 3-4v power.if u have any such ckt pls let me know.

[audioguru]

limitations for this ckt is, receiver shld be as small as possible using 3-4v power.

The circuit's LM567 PLL tone decoder has a min supply voltage of 4.75V and a high operating current so this circuit is ruled out.
Very bright green, blue and white LEDs need a supply voltage of at least 4.5V so they are also ruled out. 5 ordinary LEDs use a lot of current which requires a fairly large battery so they are also ruled out.

There are many modern IR remote control circuits on the web that operate from 3V, and there are LED flashlight circuits that use a voltage stepup IC to drive very bright LEDs from 3V. You could put the two circuits together to do what you want. ;D

[steev]

i dono much abt designing a hybrid circuit.i'll be thankfull if  can u make a such ckt design for me.
and the LED iam using here uses 3vdc supply.(i used 2 AA cells to test them).i'll use MAX 4 LED's in series.
so can u make a design for me.
i'll be waiting for ur reply.
thanks

[audioguru]

Hi Steev,
Your LEDs each need 3V. Therefore 4 in series need 12V. Right?
Wrong! LEDs need a current-limiting resistor in series to limit the current. The resistor needs voltage in addition to the voltage needed by the LEDs. Therefore you need about 18V to light four 3V LEDs in series. An 18V battery's voltage will drop to 12V during its life.

It would be foolish for me to design a voltage stepup circuit for you when there are many on the web.
It would be foolish for me to design an IR remote control circuit for you when there are many on the web.
Did you search for the circuits in Google? Try searching for Silicon Chip Never Buy Another 9V Battery. It is a project to stepup the voltage of 3V to 9V and higher. ;D

[steev]

after ur previous reply i did a small search on google for driving 4 leds using 3v dv supply.and i found one,its a voltage booster.upto here every thing is ok.but i dono how can i mix with another IR circuit(push on release off type)
pls atleast guide me towars a good ckt
thanks

[audioguru]

In Google, I entered IR Remote Control Circuit. The 1st link is full of circuits:
http://www.discovercircuits.com/R/remote.htm