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I know there is a problem is my circuit but I cant find it (Learning the basics)

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image

 

Cant seem to find a problem here or improvements but i know there should be one! could you please help me

point out away to improve my diagram image thanks everyone

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  • 0

    Your schematic shows you're using a PNP for TR1 and TR2 and it should be a NPN., the part numbers are NPN so are these the parts your using.

     

    A PNP transistor will flow current from emitter to collector, An NPN is Collector to Emitter (I know,..... i'm using practical Electronics, not Real electron flow)

     

    So you need to change it to an NPN. This is assuming the schematic is correct real components are not. And not just a drawing error with the diagram

     

    Secondly the PN108 is a photo transistor from all the data sheets I have found and as such will be very susceptible to light turning it on and off you should not be using this device for this circuit use a BC108 or  2N22222N2222 or any other general purpose NPN transistor just not a photo transistor It probably looks like it has a glass top or plastic semi transparent top on it

     

    You did not say what was the behaviour of you circuit and why you thought it was not working

     

    Hope this will help, the rest on first scan looks correct.

     

    Im betting you got these transistors from re-cycled boards or obsolete parts ??

  • 0 in reply to Robert Peter Oakes

    this diagram is for a proposed new d.c regulated power supply. it is required to produce a negative voltage of -14V with respect to ground. Thanks by the way for you help! can you spot anything else or is that all?

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