Can anyone identify this?

[johna]

Folks

I found this in a drawer today however with no instructions I don't know what it is. Could it be a flickering fire?  Can anyone reconise it please

[kevinlms]

8 hours ago, johna said:

Folks

I found this in a drawer today however with no instructions I don't know what it is. Could it be a flickering fire?  Can anyone reconise it please

It looks like it is. But why not get yourself some Alligator Clips and hook it, with a power supply and power it up and see what happens? 

Try a couple of AA batteries to give you 3 volts for starters, if nothing, reverse the red LED. If still nothing try 6 volts.

 

[RAF96]

Just in case you haven’t spotted it, the power input (polarity as shown on the board) is via the screw connector with the LED and resistor fed from the two tags.

[Crosland]

4 hours ago, kevinlms said:

It looks like it is. But why not get yourself some Alligator Clips and hook it, with a power supply and power it up and see what happens? 

Try a couple of AA batteries to give you 3 volts for starters, if nothing, reverse the red LED. If still nothing try 6 volts.

 

 

If still nothing, up the voltage until you get the flickering fire  Maybe even a smoke effect thrown in for free!

[Pandora]

Wth a magnifying glass read and post the numbers on the 14 leg chip, if it is a 555 or 556 then it is a timer circuit

[sharris]

4 hours ago, Pandora said:

Wth a magnifying glass read and post the numbers on the 14 leg chip, if it is a 555 or 556 then it is a timer circuit

 

14 pins would make it a 556 or 7556 (the CMOS version), but it seems unlikely to be that as one side is completely unused. I've done a crude flicker effect with a 7556 before, but it requires both sides being run as astables at different frequencies and mixing the outputs together. There are better ways to make a good flicker.

 

It does rather look like the manufacturer has made things more difficult by obscuring any identification on the IC. As others have said, I'd try it out and see what happens.

Edited December 22, 2019 by sharris

[melmerby]

Looks like it's designed to drive more than 1 LED as it has a plastic power transistor on the output.

There is also a reverse protection diode been added in the positive lead.

 

Some sort of adjustable flasher? (no sniggering please)

[johna]

Folks

Thanks for the advice. Probably won't get a chance to look at the board until Friday but will let you know how I get on.

[melmerby]

2 hours ago, johna said:

Folks

Thanks for the advice. Probably won't get a chance to look at the board until Friday but will let you know how I get on.

If you could read anything off the 14pin IC it would really help.

Try it at an oblique angle to the light, that sometimes makes almost illegible markings readable.

[Tricky Dicky]

I would hazard a guess that it is a logic gate astable using something like a 4011 quad NAND gate IC which is a 14 pin IC. Such an astable just requires two of the four gates with inputs linked to become inverters hence why the there are no connections on one side except for the +V pin. If it is a 4011 IC it will be good for up to 15V. The 10K trimmer and the larger capacitor I would suggest are an RC circuit controlling the pulse rate. I cannot figure out what all the other resistors and capacitors are for although one might be across the voltage rails. As someone has pointed out there is a transistor to boost the power output since the IC output is a max. 10mA. I am surprised that the inputs of the other two gates are not tied down to 0V to stop their outputs floating.

 

Richard

[melmerby]

6 hours ago, Tricky Dicky said:

I would hazard a guess that it is a logic gate astable using something like a 4011 quad NAND gate IC

 

Richard

You have a resistor from pin 6 to pin 5, pin 4 to pin 3 and pin 2 to pin 1

It looks like three time constants as there is a cap from each of pin 1, pin 3 and pin 5 to ground and resistors to each of pin 2, pin 4 and pin 6 to the 10k pot and the base of the power transistor.

 

 

I can't see how that would make an astable

(haven't quite finished the circuit diagram)

[RobjUK]

I'm guessing it is a 40106 hex schmitt inverter, configured to give three separate oscillators at different frequencies.

http://www.ti.com/lit/ds/symlink/cd40106b.pdf

 

The three outputs (and the preset) look to be summed via resistors to the base of the transistor, so it gives multiple different output voltage combinations for a flicker effect.

 

It probably needs 12V to give a good range of output levels without the LED just going out for some combinations.

Use the LED with the resistor as the board has no current limiting.

 

 

[melmerby]

28 minutes ago, RobjUK said:

I'm guessing it is a 40106 hex schmitt inverter, configured to give three separate oscillators at different frequencies.

http://www.ti.com/lit/ds/symlink/cd40106b.pdf

 

 

Sounds promising.

That would fit with where the various components go.