Transformer gone wild - DIY Chatroom

Thurman · 11-01-2009, 08:43 PM

I have a re-chargeable flashlight that came with a charger which plugs into a 110 volt receptacle and has a rated input of 15 volts DC to charge the lights battery. Today when I attempted to charge the light, the red "charging" and the green "full" LED's alternately blinked and something inside clicked rapidly. Further investigation reveals that my charger is putting out 27 volts DC instead of the rated 15 volts DC. I used a variable AC--DC power supply I had, set on 12 volts DC (as high as it would go) and the unit seems to be charging as normal. Could something have happened to the original charger and it is now delivering too much DC voltage to charge the light? I'm thinking there is a built-in safety "thingy" which would not allow the higher DC voltage to charge the battery. It sounds as if a new charger is needed. Any suggestions? Thanks, David

fltdek · 11-02-2009, 12:00 AM

Any power surges in the area lately? Not real sure but you can send me your charger - I've been looking for something that puts out 27V - 28VDC for a map light that came out of an aircraft. LOL

Whats the cost of replacing the charger? Unlikely to be something repaired.

Thurman · 11-02-2009, 02:20 PM

Hey, why not? This charger is useless to me for the intended use, and my shop has enough of those "I'll save it for something later" stuff. I checked it again this morning and it is still putting out 27 volts DC. As indicated, the hole of the tip is (+) and the outside of the tip is (-). The charger has printed on it: Input voltage-110 volts AC/output voltage-15 volts DC. But, that's not what it is doing. "fltdek"--I bet that is an acrynonym for "flight deck", what former Navy flat topper? IF you can use this charger send me some info on where to ship it--I'm serious, I don't want it if I can't use it. I'd rather see someone who can get some use out of it have it. The Halogen spotlight in question is charging fine with one of those adjustable chargers set on 12 volts DC. It may be better for it as it has a 12 volt DC battery in it. Thanks, David

Yoyizit · 11-02-2009, 03:23 PM

It must be a switcher. I can't see how a linear supply using a 50/60 Hz transformer could ever do this.

fltdek · 11-02-2009, 05:22 PM

Thurman-

I would be interested in trying it if you are just going to discard the charger. Send a blank e-mail to m.divincenzo@crewstart.com ref Charger in subject line, and I will give you my address. Let me know the shipping cost I will reimburse you or send you a gift card from Lowes or HD. Thanks.

And, it does stand for Flight Deck, but not in the military sense, - private/commercial. Figured it would sound stupid to use something, say like "cockpit" LOL

www.vatsim.net
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Thurman · 11-02-2009, 10:48 PM

fltdek: PM coming tomorrow, winding down for today after keeping sick 3 yr. old grandson with bad head cold. This swine-flu thing has me really concerned when he gets sick now.
Yoyizit: not sure what a "switcher" is. As stated, this charger (or should I call this a transformer?) has imprinted on it-120 volt AC input, 15 volt DC output, and some Chinese gibberish. No switches, or adjustments of any kind. Three tests have confirmed the 27 constant volts DC coming from the charger, and it will not work with charging the flashlight. The "charge" and "full" lights just blink alternately. The variable power supply (transformer?) set to 12 volts DC output works well and is bringing the battery back up. Hope that helps. David

Yoyizit · 11-02-2009, 11:19 PM

Quote:

Originally Posted by Thurman

not sure what a "switcher" is.

http://en.wikipedia.org/wiki/Switched-mode_power_supply
See
"Risk of equipment damage"

fltdek · 11-03-2009, 12:02 AM

Thurman -

hey, take your time, more importantly take care of your grandson, we went through the same feeling about a week ago, they had to close the girls school for two days to sterilize, there were 130+ kids that were out sick, and we ended up taking the girls to the docs, there was a 2 and a half hour wait, ironically, the school nurse showed up with her kid...so make sure he gets well. Worry about your transform/charger later.

Thurman · 11-03-2009, 12:05 PM

Wow! and Thanks Yoyizit. That's some very interesting reading. So, I suppose it is possible for this transformer/charger to be able to have an output higher than it is rated for, but maybe not safely. But, if fltdek wants it, it's his. Thanks, David
Thanks for the kind words fltdek. He is better today, has a serious case of "motor-mouth" now, but I'll take it over the way he just wanted to lay around with someone yesterday.

Thurman · 11-05-2009, 09:08 PM

I thought this was worthy of posting: I had made a call to "Ultimate Laboratories" regarding the SBS2000H3 High Output Spotlight I own which will not charge. The representative I talked to when I called told me the battery was dead and this was causing the "Charge" and "Full" lamps to blink alternately as they were doing. Due to the fact that I had the earlier model of their unit, there are no batteries available at this time. I heard: Tough luck guy, go buy you a new spotlight. Believe it or not--I got a phone call back from Ultimate Laboratories today. They asked me some common questions as to how long I had the light (app. one year), where was it bought (it was a gift, but was purchased at a Costco store in the Atlanta area), how was I using it (in my home repair business, particularly underneath homes as it lit up everything very well). I was informed that there had been a problem with the batteries in some of the earlier models and my unit was going to be replaced free of charge. I asked him to repeat that, and he did. The will ship me a new model of this spotlight, I ship them the old one back with a C.O.D. label and everyone should be happy. Maybe, just maybe--American owned businesses are starting to stand behind their foreign made products. During the discussion the techy stated that the problem of the blinking lights was one he had not heard of before, so they did need the charger as well to test the old unit. He told me he didn't understand how I could be getting 27 volts DC from the supposedly 15 volts DC output charger. It's going to be their problem now for sure. fltdeck--I'm sorry, but I have to send the charger back with the light now. Thanks, David