Electronics > Beginners
Convert 220v/50Hz illuminator to 120v/60 Hz. Safe to plug in?
Yansi:
Jeesus crist, if you have one.
Do NOT plug this thing to 110V. It will NOT work without any mod! Done deal! It is only a single range (220V+-10% or such) designed half-bridge power supply.
The output in such condition will NOT light to full brightness. Rewire at least the diode bridge to a voltage doubler!
Even if it tries to work at the low voltage, it will end up with a damage of some key components, due to higher currents required by continued low voltage operation. There are NONE undervoltage protections in such SMPS and likely even NONE overcurrent protection on the primary side. (FUSE is not an overcurrent protection for the semiconductors, FUSE is protecting against the risk of possible fire, it does not protect semiconductors!).
Or just give to someone who can mod it safely for you. :-+
mcfudge:
Those large caps are 250V 470uF, pic attached. Since I already have a 220V step up transformer, I can give it a try @220. I won't plug it into the local 120VAC without modification, as recommended.
Jwillis:
Lets look at a SMPS that has a mains input switch. Here's one I have and note what the switch does. So lets do the same to yours using a jumper wire. The frequency of the mains input makes no difference because of the primary rectification to DC.The PWM converts that DC back into a very high frequency (around 30KHz)AC square wave into the transformer.
james_s:
Trace out a schematic of the input rectifier and filter capacitors. Quite a few SMPS designs use a 330VDC bus regardless of whether they're made for 120 or 240V. The difference is that 120V models wire the rectifier and capacitors as a doubler while 240V models will full wave rectify the input. I have converted a couple of 120V devices to 240V by rewiring the input section and adding a second capacitor, the reverse is easily done too.
mcfudge:
As expected, working fine at 220v 60Hz. No noticeable heat after an hour or two. Thanks so much. Really great help here from you guys! Especially helpful watching the back and forth dialogue from the more experienced guys. I'll start on the other mods soon. Now to show someone why their nasty micro hdmi and micro usb connectors aren't working...
Myles
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version