how do I power a 12v fan from 220v without a transformer ?

[buju357]

how do I power a 12v fan from 220v , I want to use a 12v fan on 220v , doesn't matter if the 220v is ac , it will just run a bit slower.....oh , and I dont want to use a transformer.

 

[Reloadron]

1. You don't mention if the fan is AC or DC motor fan?
2. You don't mention the current draw of the fan?

Generally speaking, you don't safely and easily run a 12 VDC fan off 220 VAC mains.

Ron

 

[shortbus=]

how do I power a 12v fan from 220v , I want to use a 12v fan on 220v , doesn't matter if the 220v is ac , it will just run a bit slower.....oh , and I dont want to use a transformer.

Not very long before the smoke comes out.

 

[JimB]

Sell the 12v fan and use the money to buy a 220v fan.

JimB

 

[Froskoy]

This is probably not practical, but if you wanted to do this for academic purposes to prove that it could be done without a transformer, you could rectify the 220V AC and then use a zener diode to regulate approx. 12V for the fan, if you could find a zener diode that doesn't mind the high voltage.

 

[Jaguarjoe]

A) Buy 17 1/3 more fans and wire them in series

B) Buy a big dropping resistor

3) Make a reactance divider with a big capacitor

4) Make a triac speed controller

 

[3v0]

Some blow dryers used for hair run a small DC motor. They use the heating element to drop the voltage then feed a bridge to rectify the AC for the motor.

 

[dougy83]

doesn't matter if the 220v is ac

It kinda does matter... if it's AC there's different methods for getting your 12VDC out than if it's DC...

You also didn't mention the fan rating - so assuming a PC 12V/400mA fan. If it's larger, then you should consider using a SMPS (yes, with a transformer) for a usual converter.

For AC:
One way is to extract power from the input signal while it is <12V, i.e. (assuming sinewave) between +/-2.2 degress and 180+/-2.2 degrees of each cycle.

For DC:
you can use a buck converter. You'll obviously need a high voltage output switch.

 

[colin55]

A highly dangerous way is to use a non-polarised electrolytic and bridge.

 

[flat5]

Big light bulb and solar panel.