Rebuild 110v charger

[Baronen]

Hello

Im wondering if there is any way to rebuild this Ryobi batterycharger from 110v to 230v.
I order it from the USA and i live in Sweden.

The essayist way would of course be to buy a second charades here in Sweden or maybe a voltage converter.
Is this a simple task for someone how has low electronic knowledge, basically knows how to use a soldering iron.

**broken link removed** **broken link removed**

Regard

 

[ronv]

I see a step down transformer in your future.

 

[Baronen]

ok, thank you for you'r reply.

 

[tronitech]

It looks like a very basic design unlike the universal SMP's that accept 90~240VAC input voltage and if you input 220VAC into it's front end you're doubling the DC voltage after rectification.

What does J14 do in the middle of the front end bridge rectifier, how is it connected?

 

[MikeMl]

I seriously doubt you can operate this charger on 220V without major modifications. For starters, what voltage does the mov across the line (green thing) breakover at? What is the voltage rating of C1? Voltage rating of the rectifiers? Voltage rating of E2 and E3? etc.

 

[Diver300]

If the input circuit is arranged like the one on this circuit diagram:-
https://www.eleccircuit.com/wp-content/uploads/2008/08/200w-pc-power-supply-110v-220v-by-tl494.jpg
then it could be a simple as removing a link, as I think Tronitech was alluding to.

Also, I have seen instructions for converting chargers like this to 230 V by changing the input components. The capacitors and the main switching MOSFET would need to be rated suitably for the higher voltage.

However, don't try either unless you know how to work safely on such circuits. This is on the live side of the circuit, and it is dangerous. Mistakes will destroy the charger even if they don't hurt you.

If you buy something like this:-
https://se.farnell.com/block/sat100/transformer-auto-100va-uk/dp/1131562
it will work directly with no skills needed or danger to you.
(Sorry that is a like to Farnell, a UK company, so it is for a transformer with a UK plug. You could change the plug or find a similar transformer with a Swedish plug)

 

[JimB]

Diver300, I had a look at the power supply in your first link and there seems to be a bit of a problem.
What happens when the 110/220v switch is closed? I appears to put a short circuit across the mains.
Not quite the required effect.

To refresh my understanding of these circuits, I had a look at a few others on the web and found several which are badly drawn and at some point put a short circuit across the mains input.
One such circuit was in an application note from an otherwise well known semiconductor manufacturer, no switch involved, whoever drew the circuit for inclusion in the application note just made a complete hash of the bridge rectifier layout.

What do they say about never believing anything you find on the web?

JimB

 

[Diver300]

You are right, the circuit is drawn wrong.

https://www.eleccircuit.com/wp-content/uploads/2008/09/compaq-power-supply-200w.jpg

is better.

Looking at the circuit, it seems more likely that the OP will be able to run the charger on 220 V

In that, when the 110/220 V switch is closed, C6 is charged through one diode in the bridge when the supply is +ve and C5 is charged through the other diode when the supply is -ve. Two of the diodes are not used. The voltage is around √2 * 110 on each capacitor, so around 155 V on each and 310 V total.

When the 110/220 V switch is open, the series combination of C5 & C6 is charged by both halves of the cycle, using all four diodes, two in one direction and two in the other. R1 and R2 keep C5 and C6 at very similar voltages. The voltage is around √2 * 220, which is also 310 V.

On the original circuit, I can't see any balancing resistors, and I can't see what the capacitor arrangement is. However, having two capacitors, a link and four diodes means that it is quite possible that the circuit is similar to the computer power supply one, and cutting the link is all that it needed. The circuit must be checked first or it could all end in smoke.