Since it is an old thread, I’ve decided not to post in that and start my own one. In post #7 of this Thread , BADFLOPPY said that the Mobile Charger can be turned into +5, 0, -5 Volts supply as he said :”Just connect a reverse diode from the output of the transformer with the same capacitor and you get a twin polarity +5, 0, -5 volt”.
Better you buy a cheap Mobile Charger. Tweak the control biasing feedback and you can get + 5 volt. Just connect a reverse diode from the output of the transformer with the same capacitor and you get a twin polarity +5, 0, -5 volt PS. In india, Calcutta, a Mobile charger costs about Rs.40/- (Less than an US$).
While I was searching for simple SMPS, I found this thread, I was impresed about what BADFLOPPY said and wendered if I can get such +/- supply it will be good for some bipolar circuits.
so you want 3 terminal device , one as a source of +5V, second as neutral 0V, third as sink of - 5V .
but from where will - 5V source it current, you just cannot have a terminal sinking current without something connected to it.
if its going to sink from circuit connected, i say you use transistor to sink current , i dont know if this circuit is going to work but i am going to paste it.
select appropriate values of components connected.
While I was searching for simple SMPS, I found this thread, I was impresed about what BADFLOPPY said and wendered if I can get such +/- supply it will be good for some bipolar circuits.
I don't know what bad floppy was getting at. Since this thread is pretty old I would venture he is long gone from the forums.
When I have a need for something like this I generally go with an over the counter (store bought) solution similar to these DC to DC converters. Case in point if you look at page 15 of that data sheet and the MGFW152405 it offers +/- 5 volts out at 1.5 amps as well as 10 volts out. The input and output are fully isolated which can be nice. The input voltage can be between 9 and 32 volts making it ideal in 12 or 24 volt systems. While not quite inexpensive at about $40 USD I can't build one for less than that. Not considering time and materials anyway plus designing a board etc.
That’s nice, I'll try to contact them and conceder their product as replacement for some of our equipment, taking in mind that they give 2 in 1, 2v and 24v supply and offer 10 years warranty.
But as I told you, I'm trying to do simple SMPS to enter the world of troubleshooting. Nowadays instruments, most of them use SMPS, and when it went wrong, thousands of USD is thrown away.