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 Arlec Charger BC924 6/12/24 (Circa 1994)
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 Return to top of page · Post #: 1 · Written at 4:42:26 PM on 6 June 2018.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

Off topic for Radio but this one has fried a ceramic resistor and the thermal reset fuse is kaput. Can't read value & no info on output.

No feedback from inquiry to Arlec.


 
 Return to top of page · Post #: 2 · Written at 6:46:06 PM on 6 June 2018.
Brad's avatar
 Administrator
 Location: Naremburn, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 7290

Arlec used to make their chargers and power supplies in Australia and they were pretty good. I still have an Arlec battery charger for car batteries and it still works well. It's not close to me though so I am not sure if it is the same model as yours. Nice big plate diodes in them too.
As for the company, they are probably just like the rest now as I doubt their local factory is still a going concern. Probably just a sales office and some warehousing. Warranty and support probably goes to /dev/null.


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 3 · Written at 4:25:31 PM on 7 June 2018.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

What scares me with them is that last winter I had a couple of powerboards actually melted and the load was under the circuit breaker trip current. I have another with pilot lights for on 10/08/15 and one of them has failed already.

The charger has a date Feb1994


 
 Return to top of page · Post #: 4 · Written at 10:04:39 PM on 8 June 2018.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 2363

Marcc send us a pic and I think between us we should be able to nail it.

Is the resistor O/C? Could the failure have been due to a S/C load? Or have the diodes gone S/C?


 
 Return to top of page · Post #: 5 · Written at 8:47:35 AM on 9 June 2018.
STC830's Gravatar
 Location: NSW
 Member since 10 June 2010
 Member #: 681
 Postcount: 1253

"powerboards actually melted"

Haven't had them melt, but get warm. This was one of the cheaper ones in which the contacts are essentially strip of brass with a slot in it. So for heavy loads I make sure that I can see the claw type contacts. Like fans, another thing to be on the lookout for at op shops to replace the low quality picked up at need by the rest of the family.


 
 Return to top of page · Post #: 6 · Written at 10:55:50 AM on 9 June 2018.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

What I think has happened is that some moron reversed it, there is no protection for this resistor in such circumstances & the thermal circuit breaker has taken a hiding to the point I consider it stuffed.

As is typical, with Arlec technical (assuming they got the email) laying low, No idea what the resistor was, or is supposed to really do, other that assume it is to maintain a higher voltage on the supply side, or provide a current limiter?

My normal current limiter for dead Gel cells etc., & NiCd batteries that like to reverse polarity is a globe as a baretter.

I will remove the layers of books & accounting from one of the scanners & send scribbling's.

Seeing that I maimed one hand its paperwork day, I have a Newsletter to do, however it rained heavily, so real Mushroom hunting is next. You cannot beat their flavour.


 
 Return to top of page · Post #: 7 · Written at 1:22:04 PM on 9 June 2018.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

Finished the tour: Sent two really rough reverse engineered scrawling's to Brad. Note that I took a photo of the PCB and inverted it to show parts topside and the tracks as if they were also on the top. Relay I had not got to, but I assume that when secondary power is lost it opens the circuit to the battery.

Perhaps a big diode would have been more practical. You can use an SCR for charging & floating.

Marc

BC924 A Circuit Diagram
BC924 B Circuit Diagram


 
 Return to top of page · Post #: 8 · Written at 11:29:32 AM on 10 June 2018.
JFB's Gravatar
 JFB
 Location: Milton, NSW
 Member since 27 June 2016
 Member #: 1945
 Postcount: 55

In my BC924 the ceramic resistor is 22 Ohm 5W. What I take to be the thermal fuse, between the diode bridge and the amp meter bears the number B704836 but no manufacturer symbol in sight.

Without looking too hard, that resistor and the relay on the PC Board are associated with the BYPASS switch, so I would presume it's a current limiter.

Joe


 
 Return to top of page · Post #: 9 · Written at 1:36:47 PM on 10 June 2018.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

Thanks for that. I do need to check what happens when reverse current is applied & If there was a short & 24V the resistor would have a bit over 1A through it, & I squared R is 26 Watts, which would explain its demise. It could also have been on the high volts with a low volt battery?

These are like a valve tester where "Set the heater volts first" applies.

Note my previous post, examine my hieroglyphics, & you may be able to translate it to a circuit for yours. I would see R as a float charger?

There are handbooks offered on the WEB but some are a con & Malware bytes blocked most of them for having malicious content.

As this ones resistor as cooked the surface of the board & it will likely track. I would be tempted to remove the one in yours & perhaps replace it, with a new one and /or lift it well away from the board.


Marc


 
 Return to top of page · Post #: 10 · Written at 8:28:55 PM on 10 June 2018.
Brad's avatar
 Administrator
 Location: Naremburn, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 7290

Documents uploaded to Post 7.


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
A valve a day keeps the transistor away...

 
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