Hello everybody
Recently while randomly looking online for possible parts for the audio amplifier I am designing I came across a TV aerial with a built in amplifier that seemed perfect to solve my poor TV reception problem so I put a bid of £3.33 and won it at £3.31.
It arrived today and I tested it out and it works well. After testing it I realised that as I was holding it that it was vibrating slightly and I noticed a hum. I suspected a poorly wound transformer and used it as an excuse to open it up. I am very interested in seeing what makes things work and sometimes I will buy something that is very cheap just to take it apart.
When I opened it up I was surprised at what I found:
Seeing as I am doing lots of research into amplifiers and filters and so on I expected to find something like an amplifier. Probably a few ICs and transistors. Instead I found lots of resistors and inductors sporadically placed and only a single transistor. I must say that I am impressed that someone managed to design something like this which works. It was clearly built to a budget (saying it nicely). They even seem to have forgone the complexity of a bridge rectifier to save on diodes and gone for a half bridge with 1 diode. Interestingly enough it has an optional DC input despite having a plug and transformer built in. I would have preferred it if they had at least splashed out on a fuse.
I am wondering what you all think of the design? I must know, how on earth can this hodge podge of resistors, capacitors and inductors function as an amplifier?
Thanks
Recently while randomly looking online for possible parts for the audio amplifier I am designing I came across a TV aerial with a built in amplifier that seemed perfect to solve my poor TV reception problem so I put a bid of £3.33 and won it at £3.31.
It arrived today and I tested it out and it works well. After testing it I realised that as I was holding it that it was vibrating slightly and I noticed a hum. I suspected a poorly wound transformer and used it as an excuse to open it up. I am very interested in seeing what makes things work and sometimes I will buy something that is very cheap just to take it apart.
When I opened it up I was surprised at what I found:
Seeing as I am doing lots of research into amplifiers and filters and so on I expected to find something like an amplifier. Probably a few ICs and transistors. Instead I found lots of resistors and inductors sporadically placed and only a single transistor. I must say that I am impressed that someone managed to design something like this which works. It was clearly built to a budget (saying it nicely). They even seem to have forgone the complexity of a bridge rectifier to save on diodes and gone for a half bridge with 1 diode. Interestingly enough it has an optional DC input despite having a plug and transformer built in. I would have preferred it if they had at least splashed out on a fuse.
I am wondering what you all think of the design? I must know, how on earth can this hodge podge of resistors, capacitors and inductors function as an amplifier?
Thanks