Simple Infrared LED Switch Help

[amansammy]

Hello everyone! This is my first post on this forum.

Basically I want to make a simple LED lamp which would take about 9V. For it I want to create an Infrared switch so that I can switch the lamp on with any remote(my TV remote mainly!). I have got an Infrared receiver ( TSOP1738 )http://www.erodov.com/forums/imagehosting/221493a3cd13fa7b.jpg
I also have a 4017 counter, bc547 and bc557 NPN transistors and also common resistors and capacitors.
Currently I am eyeing this circuit http://embedded-lab.com/blog/wp-content/uploads/2011/07/IR_RemoteCkt.jpg but this is used to switch on AC Appliances.
Can you give a modification for the circuit to switch on/off the led lamp? Or any other circuit for this? Please help.
Thank You

 

[BobK]

You could use the circuit as is, using the relay to switch your LED lamp. But if the LED is not using a lot of current (1A or less) you could just replace the BC547 with a higher power transistor and adjust the base resistor as needed, then place the LED lamp where the relay coil is connected, letting the transistor do the swtiching.

Bob

 

[amansammy]

You could use the circuit as is, using the relay to switch your LED lamp. But if the LED is not using a lot of current (1A or less) you could just replace the BC547 with a higher power transistor and adjust the base resistor as needed, then place the LED lamp where the relay coil is connected, letting the transistor do the swtiching.

Bob

Would a 2N2222 or 2N3904 will be okay to replace the BC547? And what should be the resistor value? Does it has to be of smaller value or larger? Sorry but I am a newbie in electronics.

 

[(*steve*)]

The BC547 has a much higher gain than these transistors, but in this circuit I don't think it would matter.

 

[amansammy]

would the bc547 be okay? and what about the base resistor? thanks for the quick replys.

 

[amansammy]

You could use the circuit as is, using the relay to switch your LED lamp.

I don't have a 5v relay. Can I use a 12v relay instead?

 

[BobK]

What is the voltage / current of the lamp you are trying to switch? This is important for deciding how to do it.

You could use a 12V relay, but you would have to have a 12V supply then in addition to the 5V supply.

Bob

 

[amansammy]

My lamp actually are 10 3v White LEDs connected in parallel. Each LED takes in 20mA so total current is 200mA. I do have a 12v supply at the moment.

 

[BobK]

Then just replace the transistor with the 2N2222 and make the base resistor 1K. This would provide a base current of about 3.5 ma which should be enough to saturate the transistor. Connect LEDs + resistors to the collector and the then to the positive supply. No relay needed.

Bob