IR receiver oscillates if powered by rectified source. help?

[folarinv]

I constructed an infra-red receiver using IR-sensor from TV, schmitt trigger-4093, monostable-555, flip-flop:4013, transistor and relay. I'm using this receiver to switch on/off a lamp. The problem with the circuit is that if i power it with a rectified voltage source, the lamp will start going on/off by itself (oscillation) but if i power it from a 9V battery source, the circuit behaves properly.

How can I modify the circuit so that I can power it with a rectified voltage source as the 9V battery gets drained within minutes.

 

[Nigel Goodwin]

Re: IR receiver oscillates if powered by rectified source. h

I constructed an infra-red receiver using IR-sensor from TV, schmitt trigger-4093, monostable-555, flip-flop:4013, transistor and relay. I'm using this receiver to switch on/off a lamp. The problem with the circuit is that if i power it with a rectified voltage source, the lamp will start going on/off by itself (oscillation) but if i power it from a 9V battery source, the circuit behaves properly.

How can I modify the circuit so that I can power it with a rectified voltage source as the 9V battery gets drained within minutes.

If you mean a three pin IR receiver IC?, these need seperate supply decoupling, feed the IC power through a resistor with a decoupling capacitor - check my IR PIC tutorials for details of suitable values.

 

[Dr.EM]

I think you need to add a large capacitor after the rectifier, and a voltage regulator after that. This will lower the output voltage, but should fix your problem.

 

[folarinv]

regulated power supply did not work

I used a 9V regulated power supply taken from an hobbyist kit but it did not stop the oscillation.

Nigel, I'm not clear with your suggestions when u said i should decouple the power supply to the 3-pin IR receiver. Secondly, your PIC tutorial site talks about programming. I couldn't find much help there.

 

[folarinv]

Re: IR receiver oscillates if powered by rectified source. h

I constructed an infra-red receiver using IR-sensor from TV, schmitt trigger-4093, monostable-555, flip-flop:4013, transistor and relay. I'm using this receiver to switch on/off a lamp. The problem with the circuit is that if i power it with a rectified voltage source, the lamp will start going on/off by itself (oscillation) but if i power it from a 9V battery source, the circuit behaves properly.

How can I modify the circuit so that I can power it with a rectified voltage source as the 9V battery gets drained within minutes.

If you mean a three pin IR receiver IC?, these need seperate supply decoupling, feed the IC power through a resistor with a decoupling capacitor - check my IR PIC tutorials for details of suitable values.

Nigel, I'm not clear with your suggestions when u said i should decouple the power supply to the 3-pin IR receiver. Secondly, your PIC tutorial site talks about programming. I couldn't find much help there

 

[Nigel Goodwin]

Re: IR receiver oscillates if powered by rectified source. h

Nigel, I'm not clear with your suggestions when u said i should decouple the power supply to the 3-pin IR receiver. Secondly, your PIC tutorial site talks about programming. I couldn't find much help there

Look at the hardware pages for my tutorials, the one for the IR tutorial shows how to connect IR receivers - the exact page is . It uses a 47 ohm resistor and a 47uF capacitor, these decoupling components are VITAL!.

 

[zachtheterrible]

I used a 9V regulated power supply taken from an hobbyist kit but it did not stop the oscillation.

If you have an oscilloscope, look at the 9 volts. It is probably rippling w/ a 60hz sine wave. Or try powering a radio or something that usually requires a 9 volt battery with it and you will probably be able to hear a hum.

My point being is that your power supply is probably nowhere near being clean.

 

[folarinv]

Re: IR receiver oscillates if powered by rectified source. h

Nigel, I'm not clear with your suggestions when u said i should decouple the power supply to the 3-pin IR receiver. Secondly, your PIC tutorial site talks about programming. I couldn't find much help there

Look at the hardware pages for my tutorials, the one for the IR tutorial shows how to connect IR receivers - the exact page is resistor and a 47uF capacitor, these decoupling components are VITAL!.

Thanks Nigel.

The circuit seems to be stable now. I've been testing it for over 48hrs and
it has not make any unsolicited switching.I used a 470resistor and 47uf capacitor for a 9V power supply. I just hope it remain stable forever.

 

[Nigel Goodwin]

Re: IR receiver oscillates if powered by rectified source. h

The circuit seems to be stable now. I've been testing it for over 48hrs and
it has not make any unsolicited switching.I used a 470resistor and 47uf capacitor for a 9V power supply. I just hope it remain stable forever.

It should do, you shouldn't have left them out in the first place, as I said before they are absolutely vital for these IR receiver IC's.