remote control operated switch for room light

[amritsen]

Hello everyone,
I am designing a circuit for remote controlled operated switch for the household lighting, circuit is taken from efy projects.
I am using 5 v DC supply for the circuit, here I have some questions regardin the circuitory,
Here I have to put a transistor BC 558, can we use a transistor BC 548 in place of BC 558, if not thenwhat are the effects if I do So??

 

[amritsen]

One more question ,, can any IR remote can be used for this ciruit ??

 

[Les Jones]

If this is the circuit YOU designed then I do not see why you need to ask these questions. To use an NPN transistor in place of a PNP transistor would require re designing that part of the circuit. As the IR receiver you have chosen is designed for a 38 KHZ carrier then it will only work with remote controls that use that frequency.

Les.

 

[amritsen]

Thanks Jones
Actually I didn't design it .. I just copy the circuit from efy projects website .. i am soldering the components at this moment ..but right now I don't have the BC558 transitor .. i want to replace this transistor by something else..please suggest some other options for the replacement of BC 558..

 

[alec_t]

No, you can't use a BC548 (it must be a PNP type). Alternatives include 2N3906, 2N5807, BC557, BC857 etc.

 

[amritsen]

Ya..558 is PNP and 548 is NPN..I am searching for the transistors you suggested .. thanks

What is the ir frequency used band in General tv remotes ??

 

[Les Jones]

I would think a 2N3702, 2N3906, BC557 or BC327 should work. While looking at the data on the TSOP1738 I noticed that the maximum output current rating is 5 mA There is nothing in your circuit to limit the output current. I would suggest adding a 1K resistor from pin 3 of the TSOP1738 to the junction of C1+ and the base of T1

Les.

 

[amritsen]

I think any TV REMOTE control can switch this circuit on off .. work is under progress ..

 

[Les Jones]

I think 38 Khz is most common but as this range of IR receivers is also available for 30, 33, 36 36.7, 40 and 56 Khz then any of these frequencies may be used.

Les.

 

[amritsen]

Thanks les
I got BC 327 25 from my garbage. . . I think it will work in place of BC558..

 

[KeepItSimpleStupid]

Not having the "right" IR receiver, generally just messes up sensitivity.

 

[amritsen]

so let me know some other options ,,, if IR reciever is not good,, ?

 

[alec_t]

Might be cheaper to buy an off-the-shelf "wireless light switch".

 

[AnalogKid]

2N2907, 2N4403

 

[Nigel Goodwin]

so let me know some other options ,,, if IR reciever is not good,, ?

IR is fine, but NOT the way you're trying to use it.

The actual receive frequency of the IC seems to make very little difference, it just reduces the range slightly if it's wrong - but what's essential is some kind of coding system, and most probably a processor either end to code and decode the signals.

There are PIC examples in my tutorials, using the Sony SIRC's system, and these could be easily used to do exactly (and reliably) what you're trying to do - in fact tutorial 5.3 already allows you to turn 8 LED's ON and OFF using a Sony TV remote.

 

[Reloadron]

While IR would not be my first choice, if I did use the IR method I would start with one of these for under $10 USD. I would likely use an RF relay board with a keyfob. Units like this one are common in two and four channel versions.

Ron

 

[Les Jones]

I do not believe that this design uses any coding. The 100 uF capacitor C1 will filter out the normal codes sent by the remote. I think pressing any button (Probably longer than a normal press.) will toggle the power on and off. This is my understanding of how it is intended to work. Any burst of infra red will pull the output of the TSOP1738 low (As C1 will filter out any fast pulses.) This will turn on T1 causing the clock signal to the 4017 to go high which will step it to the next state. If it is in state 0 (Output off.) then it will step to state 1 ( output on.). If it is in state 1 it will step to state 2 which will cause a reset to state 0 (As output 2 is connected to the reset input.)

Edit. I cannot see a link on your circuit between pins 4 and 15 of the 4017. Also a picture taken from directly above the board would help.

Les.

 

[AnalogKid]

Correct, it is a simple envelope detector and the equivalent of a toggle flipflop. The chip has an internal 100K pull up and an NPN output transistor. 38kHz bursts discharge C1 until T1 turns on and presents a positive edge to the 4017 clock input. T1 turns off at around 4.5 V, or 90% of Vcc. 95% would be three time constants (30 seconds), so how soon the circuit will respond to another button push depends on how long the last one was. After a long received pulse the circuit will not see another valid input for about 30 seconds.

There should be a 47 uF decoupling cap from pin 2 to GND.

ak

 

[KeepItSimpleStupid]

I have one of these http://www.tauntek.com/tinyir2-learning-ir-remote-control-receiver.htm that I purchased for a project that I never completed. You could then take a relatively unused key on a remote and use it.

 

[amritsen]

Hello everyone .. .
I have completed the circuit .. but output is not coming from pin no.2 of the ic ..
I have used
Ic 4017BE

please help how can I make this in working condition ...

Les .. plz help..