220v strobe running at low power on 110v to 220v transformer -- advice?

Thread Starter

llqh

Joined Mar 27, 2021
15
have a 220 volt 1500 watt strobe that has a very simple motherboard inside....it runs direct from the 220v main...no internal capacitors.


Max strobe rate is less than 15 pulses a second.

At the input of the board there are four large diodes, apparently to change the 220v input to DC.

The problem is I often rent a home that does not have 220volt, but only 110v.

Then I run the strobe on a 110-220v transformer. The transformer is a good one, with a torrid coil, and rated at 5000v.

But this transformer cannot supply the instant 1500watts to the strobe and so the strobe is perhaps 50% of the output then when operating at a line voltage 220.

I am thinking of inserting a large capacitor just after the input diodes (bridge?), in series between the diodes and the rest of the board.

Would this work, and if so, what should be the type / rating of the capacitor?

(I'm a software engineer...not electronic)

Thanks
 

Thread Starter

llqh

Joined Mar 27, 2021
15
here you can see the motherboard...I have two...they are exactly the same...one seems a little longer but it is because the components on the other are on the bottom and raise it a little

on the top is the 220 AC line input...directly to two sets of two diodes, one set for each line input

I suppose on the downside of the diodes is 220v DC (I'm not an electrical engineer)....and that I can simply put a large capacitor there.

....would this work....to unsolder the output side of the capacitors (they all solder into a common circuit on the motherboard)

and then insert a large capacitor there, in series between the output side of the capacitors (all four together) and the common circuit on the motherboard.

if that would work, then what type/size/specifications would I need

the idea is that the 110-220v transformer cannot supply the instant DC current needed for the strobe (a 220v line will)

and that the capacitor will buffer the 220v DC current

the 1500watt strobe only needs the power to produce the flash in the Xenon tube,strobe.jpg which I imagine is actually not a large amount of current to flas 15 times a second
 

Dodgydave

Joined Jun 22, 2012
10,306
I don't understand why the four large diodes are designed to short out the AC input , unless they are zeners??

Can you take sharper pics of the components and the 14 pin chip please..
 

Thread Starter

llqh

Joined Mar 27, 2021
15
this is really a cheap motherboard out of China...but it works great for what I need...and it is not sensitive to the frequency (50/60 hz)

some of the fancier strobe motherboards only work with 50hz 220v.
 

Dodgydave

Joined Jun 22, 2012
10,306
The chip is a CD4093 quad Schmidt nand gate, that works from 5v to 15v dc, where is the other chip?
Can you mark on the pcb where the mains comes in , it looks to me like the terminals marked as 3 at the top.
 

Thread Starter

llqh

Joined Mar 27, 2021
15
the other chip is on the bottom left between the two plug jacks...it is yellow and marked 4N35 K644
 

Thread Starter

llqh

Joined Mar 27, 2021
15
I believe the mains comes in at the top, soldered into P1 and P2 boxes (letters are sidways) , which go directly to the input side of the diodes. Each side two diodes.

Will verify that tomorrow..these are spare boards and I'll take off the strobe cover tomorrow and verify
 

Thread Starter

llqh

Joined Mar 27, 2021
15
on the top right is an SCR, between two resistors, seen from the top labelled K C4793 675

and to the left of it is a green cap which is shadowing for small diodes
 

Thread Starter

llqh

Joined Mar 27, 2021
15
I"M TOTALLY INCORRECT

...sorry... these were spare motherboards...when I opened the strobe I see that it is wired differently than I assumed (never make assumptions...)

will have to dismantle it more to see what the connection points are
 

Ian0

Joined Aug 7, 2020
5,139
Buy a better strobe.
As there is no capacitor to store energy,your cheap and nasty strobe relies on getting a high current from the mains for a very short period of time, more than your transformer can supply. It would probably fail all EMC regulations
 

Thread Starter

llqh

Joined Mar 27, 2021
15
Well, I'm using this strobe to power a PEMF circuit...it works really good for that where the more expensive 220v strobes don't work at all with a 60hz current....will repost the pics with a correct input ouput.

Yes, it is nasty, but it works very good for what I need with a 220vac 60hz direct mains input.
 

Thread Starter

llqh

Joined Mar 27, 2021
15
By the way I don't live in a first world country where everything works "perfectly". Much less the electric grid. A very nice fancy strobe will not work here. :)
 

Thread Starter

llqh

Joined Mar 27, 2021
15
the original description is NOT CORRECT

I dismanted the strobe to see what the actual connections are.

mains input (220vac) is via the red wires. Output across the xenon tube are the white wires. The silver is the strobe trigger.

so, looks like one of the outputs is directly connected to the main

there are small red and black wires that go to the 12v fan

the "large" brown capacitor is a MPP 225K 2H / C0607204 E

maybe replace that capacitor with one much larger?
 

Ian0

Joined Aug 7, 2020
5,139
By the way I don't live in a first world country where everything works "perfectly". Much less the electric grid. A very nice fancy strobe will not work here. :)
It stands a much better chance than one that relies on taking 100Amp pulses from the mains.
 
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