Power supply for dynamo

[Grthebigg]

Hi to the members,
I have a DC 90v 10A Electromotor . I want to make a power supply without transformer for this .
My town voltage is AC 230v 15A.
i think about half wave rectifier , but i have not electronic professional speciality for calculations.
Please help me
Cheers,

 

[dick_freebird]

I would break this into two problems. One is motor-
as-generator to battery, so you have some power
when the prime source is absent (like wind or solar).
This is charge controller and output control (source
from battery if no prime power, prime power if it is
present). This could be simple if the battery is
tolerant of overcharging (as are many automotive
lead acid types; newer, better, fancier chemistries
tend to be more fussy and fragile). A shunt regulator
is simple, wasteful; a shunt that puts waste power
to some other use (like well pump, DC powered
refrigerator / ice maker, etc.) would put that to good
use. A series regulator can do a good job of precision
charge control but is more work.

The other is battery (and/or motor) to AC, an inverter
to get wallplug power. That is a trickier build, seems
like a lot of people have a lot of trouble with inverter
designs they find on the Internet; research ones you
think you like, for comments about how well they
work, if they work.

 

[Easy peasy]

Two solutions, get a single phase AC generator with a built in AVR card ( AC voltage regulator card ) as run this off the shaft the dynamo was going to run on assuming the shaft speed is approx constant and can be made to match the speed required for 50/60Hz out ( 3000 rpm typ - but can be lower ) - this is the most efficient approach

2ndly, rectify and smooth the 90V 10A ( ~ 900 watts ) and run this into an inverter ( 110VDC input type ) as long as your loads are < 850watt and the source can provide 900 watt or a bit more shaft power - you will be fine - 1kW or 1.5kW inverter

 

[BradtheRad]

DC 90v 10A Electromotor. I want to make a power supply without transformer for this .
My town voltage is AC 230v 15A.
i think about half wave rectifier

Seeing this gives me the impression you wish to drop house voltage to provide 90 VDC. Your load calculates as 9 ohms. A half-wave power supply (one diode) admits extreme Amperes per cycle (or rather half-cycle). Your house wiring might introduce some amount of resistance. In any case output voltage is unpredictable.

By installing an inductor, or coupled inductor, and/or capacitors, it's conceivable you can create sufficient voltage drop (with diode rectification) so as to provide your desired output. Power factor error ought to be considered.

 

[Easy peasy]

Oh, you want to power the 90v 10A motor from the mains supply..? - sorry you need a transformer to make it safe - or a cheap Chinese 900V power supply - you could use a half driven bridge of 2 diodes, 2 SCR's to limit the effective output to 90V DC average and use the inductance of the motor to smooth the current a little - can you design a half controlled bridge?