Zexum EFS Electronic Starter Disassembled & Repaired

The first one of [url=http://80.229.24.59:9232/gallery/displayimage.php?pid=8937][u]these[/u][/url] used starters I bought a while ago failed today. Sometimes it would strike tubes fine, others not & tubes kept restarting when operating normally. I opened it up and found that simply one of the legs had snapped out of the pins. A quick solder up later and it's working good as new again.

Whilst it was apart I took this picture of its inside bits so you can see what's in it. The 3-legged component that cannot be read is marked 'C945 G528'.

Zexum EFS Electronic Starter Disassembled & Repaired


The first one of these used starters I bought a while ago failed today. Sometimes it would strike tubes fine, others not & tubes kept restarting when operating normally. I opened it up and found that simply one of the legs had snapped out of the pins. A quick solder up later and it's working good as new again.

Whilst it was apart I took this picture of its inside bits so you can see what's in it. The 3-legged component that cannot be read is marked 'C945 G528'.

20190121_180749.jpg 4x4_Vintage_Mod_Gear.jpg 20190108_140644-1.jpg IMG_20181229_070843.jpg IMG_20181213_013836.jpg
File information
Filename:20190108_140644-1.jpg
Album name:fluorescent / Control Gear
Manufacturer:Zexum
Type/Model:EFS
Wattage:For 4-125w Fluorescent Tubes
Filesize:1723 KiB
Date added:08 Jan, 2019
Dimensions:2445 x 1452 pixels
Displayed:60 times
URL:http://80.229.24.59:9232/gallery/displayimage.php?pid=10017
Favourites:Add to Favourites

Comment 1 to 16 of 16
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Simon_R   [08 Jan, 2019 at 11:35 PM]
Neat repair...I'm a big fan of electronic starters!
fluorescent   [09 Jan, 2019 at 12:22 AM]
Electronic starters are pretty much all I'll use now. These were dirt cheap from eBay and I thought they'd be crap TBH, but I actually really like these ones!
Slyspark   [09 Jan, 2019 at 12:27 AM]
Same, about to bulk-buy another batch of LEL ones. Seem to get through loads. Still, saves the ballasts from being fried!
fluorescent   [09 Jan, 2019 at 12:45 AM]
And extends the life of tubes, significantly if switched regularly. What's not to love about them?
Slyspark   [09 Jan, 2019 at 01:14 AM]
Agreed! Modern starters (glow bottle ones) almost all are Chinese now and stick constantly. I won't touch them any more.
fluorescent   [09 Jan, 2019 at 01:30 AM]
Totally agree with that, modern ones are all garbage that I've used & I don't trust them... I do have some good old starters in the collection, Holland made Philips and GB made Thorn's etc, but I just can't bring myself to use them! I dislike the 'potluck' starting; sometimes a good preheat, sometimes a cold start, repeated failed start attempts etc. It's just not efficient and is shortening the life of my tubes at every start up.
Slyspark   [09 Jan, 2019 at 01:39 AM]
You might find some of those older starters song work now anyway. There's a reason for that.... Radioactive decay....
FrontSideBus   [09 Jan, 2019 at 01:44 AM]
Aother hand in the air for LEL Multipulse here.
Slyspark   [09 Jan, 2019 at 01:53 AM]
Just watch out tho, the Arlen EFS600 seem to be going the way the other glowbottle starters are, had loads of problems with those, which is why I now use LEL Multipulse. Plus, the LEL ones are made less than an hour from here!
fluorescent   [09 Jan, 2019 at 02:00 AM]
They're BG now so that doesn't surprise me. If I had to order a load of new starters, I would go for the LEL's
Slyspark   [09 Jan, 2019 at 02:15 AM]
Yes, I think that's largely the problem!
Danny   [09 Jan, 2019 at 02:27 PM]
Is there any of these still on ebay? I dont mind the LELs myself. But dont like the EFS600s. They wont start 8 foots. And i dont like the Thorn Vivatron 5s they are weak as fuck
Ash   [09 Jan, 2019 at 08:49 PM]
The C945 is probably a 2SC945 - fairly generic small signal NPN transistor. I find it mch weirder that the switching element here is a MOSFET, it used to be an SCR in all previous starters
fluorescent   [10 Jan, 2019 at 06:14 PM]
I'm not too clued up on electronics. Would a MOSFET be cheaper or better suited to the task perhaps?
Ash   [10 Jan, 2019 at 08:49 PM]
I guess it would be cheaper for the component, but the thing with SCRs (and thyristors in general) is that they are controlled very differently from MOSFETs and other transistors : They are switched on (or for GTO's, also off) by a single pulse and drop out at AC zero crossings on their own, while transistors are controlled ultimately by the signal at their gate/base at the very moment. Therefore thyristors are naturally well suited for many AC applications, and may negate cost disadvantages by needing simpler control circuits

In the case of the starter it is less clear, as the component (whatever it is) needs a way to be forced to the off condition before the zero crossing, in order to generate the pulse from the ballast. Maybe in this application the hack needed to switch off a MOSFET would not be that much more complicated from what's needed for an SCR

Also, elctronic starters have been built for years around 2 common SCRs made specifically for them, which might have included some more circuitry inside which we dont know about. The SCRs are ST TN22 and PI Y1112
fluorescent   [21 Jan, 2019 at 03:07 PM]
Whilst this one is still working fine, one of the others failed today. Stuck closed.

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