How can I frap up a power adapter?

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geekIT

2420 posts

Uber Geek

#154723 5-Nov-2014 17:01

Hi all. I have a Black & Decker rechargeable drill.
It's fairly old now but still works well.
Except for the power adapter - it's just just packed a sad and no longer outputs any current.
Its output is 14.5v DC x 210 ma.
Anyone know of a way I can bodgie up a substitute adapter?

'Those who can make you believe absurdities can make you commit atrocities.' Voltaire

'A patriot must always be ready to defend his country against his government.' Edward Abbey

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840 posts

Ultimate Geek

#1169409 5-Nov-2014 17:05

Jaycar have a whole series of 240 to ##v dc power adaptors that can be set to verious outputs and have multipule plug fittings

geekIT

2420 posts

Uber Geek

#1169411 5-Nov-2014 17:10

Good call, I'll give them a bell :-)

'Those who can make you believe absurdities can make you commit atrocities.' Voltaire

'A patriot must always be ready to defend his country against his government.' Edward Abbey

Aredwood

3885 posts

Uber Geek

#1170585 7-Nov-2014 10:21

If you can't find a 14.5V one. Get a 15V output one and wire a standard diode (not an LED) in series with with the output. That will give you 0.5V voltage drop.

geekIT

2420 posts

Uber Geek

#1170896 7-Nov-2014 14:40

InstallerUFB: This is the only offering that Jaycar could suggest. Is it appropriate?
-----------------------------------------------------------------
25W 9 - 24VDC Regulated Switchmode Plugpack These switchmode plugpack adaptors are slim in size, lightweight, and feature manually selectable variable voltage outputs.

All are MEPS compliant and come supplied with 7 plugs. (MP-3318 does not include USB socket)

25W 9 - 24VDC Plugpack Cat No. MP-3318
Specifications:
• Input voltage: 100 - 240VAC
• Output voltage: 9, 12, 13.5, 15VDC @ 1.5A
18, 20VDC @ 1.2A
24VDC @ 1A
---------------------------------------------------------------
Aredwood, thanks for your input. Would the above adapter work if it was modified in the way you suggest?

'Those who can make you believe absurdities can make you commit atrocities.' Voltaire

'A patriot must always be ready to defend his country against his government.' Edward Abbey

ubergeeknz

3344 posts

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Trusted

Vocus

#1170899 7-Nov-2014 14:46

There's a good chance the power adapter is unregulated and actually drops to a reasonable voltage to charge the batteries due to the low current output available. So be careful using a high-powered, regulated supply with this drill. A better bet than a diode IMO would be a chunky resistor to limit the current output to 200 odd ma.

Aredwood

3885 posts

Uber Geek

#1170905 7-Nov-2014 14:58

Yes would work fine. but get the jaycar mp-3492 instead. As it is cheaper and can output more current. Unless you want the multi output voltage function. As for the diode, something like the jaycar zr-1004 would work for the load you have. But will blow up if you try to use the power supply to it's full capacity. Get the zr-1024 instead, sure it's current rating is overkill. But you will be highly unlikely to blow it up. As for wiring it in, it has to go in series the correct way around. If it is the wrong way around, it won't damage anything. But won't work (just swap it around).

geekIT

2420 posts

Uber Geek

#1171313 8-Nov-2014 13:24

Thanks Aredwood. So you mean this adapter:
http://www.jaycar.co.nz/productView.asp?ID=MP3492&w=MP-3492&form=KEYWORD
With a ZR1024 diode patched into the line somewhere?
http://www.jaycar.co.nz/productView.asp?ID=ZR1024

'Those who can make you believe absurdities can make you commit atrocities.' Voltaire

'A patriot must always be ready to defend his country against his government.' Edward Abbey

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richms

28187 posts

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Lifetime subscriber

#1171318 8-Nov-2014 14:02

The problem with old power adapters for charging cheap power tools is they rely on the transformer construction as the current limit, with no active electronics. That is why the efficiency is so crap on them, and also why you cant actually use them to power anything else. They then just use the fact that you can abuse nicd cells with no immediate disastorous results and put in small print in the manual to not leave it on charge for more than X hours to get them off the hook for all the battery failures from the aweful way they treat the cells.

Chances are its like my old cheap nasty makita and the DC in jack is connected straight to the cells. If you plug in a nice constant voltage wall adapter it will either cook the cells, or it will just go into protection mode and not achieve anything.

I just used my cheap hobby charger on the NiCd option to charge that drill while it lasted.

Richard rich.ms

geekIT

2420 posts

Uber Geek

#1171402 8-Nov-2014 18:04

richms, thanks for your input, but I'm sorry to say that I have no idea what you said :-(

'Those who can make you believe absurdities can make you commit atrocities.' Voltaire

'A patriot must always be ready to defend his country against his government.' Edward Abbey

Aredwood

3885 posts

Uber Geek

#1171881 9-Nov-2014 23:40

Another way of explaining what Richms said. Old and/or cheap powertools sometimes use crappy power supply's as a rudimentary means of charging regulation. If you upgrade the power supply you might blow up the tool. or at least ruin the battery. In short only do it if you won't care if it dies soon afterwards. And as richms said, watch the charge time. And yes those 2 items you linked back are the right ones. If the store doesn't have that exact diode, just choose another one that is marked in the Jaycar catalogue as SSR (standard silicone diode) Get a copy of the book catalogue when you are at Jaycar if you haven't already. Much better than trying to use their website.

richms

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#1171887 10-Nov-2014 01:20

Except a dead flat nicd or nimh will pull way too much current with just a diode to drop voltage and it will trip the protection in the power supply.

Richard rich.ms

Aredwood

3885 posts

Uber Geek

#1172523 10-Nov-2014 23:51

And if that happens, Just add a 12V 10W light bulb in series as well. The light acts as a good current limiter. It basicly behaves as a positive temp coefficient resistor. It will make the charging take ages, but it will still work.

geekIT

2420 posts

Uber Geek

#1174967 13-Nov-2014 09:20

By way of more information, here's a link to a parts site in the US that purports to have a few chargers for sale:
http://www.ereplacementparts.com/black-and-decker-cd120g-type-volt-drill-driver-parts-c-4167_4168_11960.html
I've emailed them re shipping and availability but I'm not optimistic about cooperation.
Also had to grin when I did a search for the drill - CD120G-XE - and found 3 TradeMe listings for the model, all for sale cheap because the chargers had failed :-)

Aredwood, I might have to go for your suggested fix. Any chance you could elaborate about the method? Like, am I right to assume that the diode and\or light bulb would be soldered across the phase (?) or neutral (?) line? Or is it not 'pc' to describe this sort of 'bodgie work' on Geekzone? I guess we never know these days when there might be an OSH inspector hiding in the shrubbery, lol. Shucks, I miss the good old days when we could risk our silly necks with all kinds of dangerous lunacy without worrying about granny-like mollycoddling by the State. Obviously the Govt is trying to save needless ACC expenditure, I guess.

PS: I'm gobsmacked at your OOKLA test. I get 12.3 Mbps :-(

'Those who can make you believe absurdities can make you commit atrocities.' Voltaire

'A patriot must always be ready to defend his country against his government.' Edward Abbey

ubergeeknz

3344 posts

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Vocus

#1174982 13-Nov-2014 09:55

geekIT: Aredwood, I might have to go for your suggested fix. Any chance you could elaborate about the method? Like, am I right to assume that the diode and\or light bulb would be soldered across the phase (?) or neutral (?) line? Or is it not 'pc' to describe this sort of 'bodgie work' on Geekzone? I guess we never know these days when there might be an OSH inspector hiding in the shrubbery, lol. Shucks, I miss the good old days when we could risk our silly necks with all kinds of dangerous lunacy without worrying about granny-like mollycoddling by the State. Obviously the Govt is trying to save needless ACC expenditure, I guess.

PS: I'm gobsmacked at your OOKLA test. I get 12.3 Mbps :-(

WHOA there. He means in series with the low voltage output of the transformer. Not the mains. The bulb will act to limit the current flowing into the batteries (basically acting as a resistor)

geekIT

2420 posts

Uber Geek

#1175019 13-Nov-2014 10:38

Sorry, I meant the output of the transformer, not its input. To my almost-lay outlook of things electrical, the hot line is still hot whether it's 240v,10v, 1v, AC, DC, red, brown or yellow.

'Those who can make you believe absurdities can make you commit atrocities.' Voltaire

'A patriot must always be ready to defend his country against his government.' Edward Abbey

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