How to transform 2vdc to 240vac

[ajbwarrrior]

i have just recently discovered peltier devices which make electricity from the Seebeck effect. one video on you tube showing peltier device producing about 2 volts from a flame. i would like to know how to convert this 2 volts DC (if it is actually dc) into 2 volts AC then put it through a step up transformer to get higher voltages.

 

[davenn]

hi there
welcome to PF

well you could take the 2VDC and with an oscillator produce an AC Voltage, then feed that into a transformer. There will be losses in the transformer to consider.
the other thing to consider is that every time you double the Voltage you will halve the available current. ie. say your original 2VDC has 500mA ( 0.5 Amp) capability, you double that to 4V and you are only going to have 250mA. You can see that by the time you get it to a really high Voltage the current capability at that Voltage is going to be VERY low

Dave

 

[ajbwarrrior]

thanks Dave, so what could actually function at 240vac at a really low current?

 

[davenn]

thanks Dave, so what could actually function at 240vac at a really low current?

Yes, but practically it wouldn't be of much use other than an experiment.

now lift your DC voltage and current supply up a bit and you start to get something more useful like this example...

just a quick explanation...

T1 and T2 are part of a multibivrator oscillator circuit. They are connected respectively to 2 pair of driver transistors, T3,4 and T6,7. Those pairs of driver transistors control the 2 x 2N3055 power transistors, T5,8.
The 12VDC supply is connected to the collectors of T5,8 via each half of the transformer windings. T5 and T8 are switched on and off alternately by the oscillator, this produces a low voltage square wave oscillation in the secondary of the transformer of roughly 18V peak to peak resulting in a ~ 220V output in the primary of the transformer.
This is a square wave inverter and for many applications its quite useable. However some equip requires a clean or at least relatively clean Sinewave 220 (110)VAC.

I just present this to give you a bit of an idea of what is involved in a basic DC to AC inverter :)

cheers
Dave

 

[DrDu]

thanks Dave, so what could actually function at 240vac at a really low current?

E.g. a flash light where you just have to charge a capacitor.
Or ionization chambers. With about double the voltage (>400V) you can also run a Geiger Mueller counter.

 

[ajbwarrrior]

thanks for the explanation. it would be great if the 2VDC could be turned into a useful 240VAC.

 

[CWatters]