Replacement transformer for sweeper

I have a 12v Model CFV Type 1 Black & Decker Cordless Floor Vac which uses a 12v transformer which I have temporarily misplaced. In the meantime, I found one which I'd like to try out, with two different settings -- one with 100 mA and the other with 300 mA output. Would either of these two settings work OK?

Thanks digger

Reply to
digger odell
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read the label on the vac to see what it draws. pick a number on the transformer higher than that.

Reply to
charlie

That information "might" be in the missing manual but the only lable is on the base plate, dontaining the model number and the fact that it is

12vdc. My simple minded thought is that the battery would simply charge in less time if I set the transformer on 300mA. I even have another charger which supplies 700mA.

Is there any danger of damaging the battery from using a trickle charge that is less/more than what's recommended?

digger

Reply to
digger odell

That information "might" be in the missing manual but the only lable is on the base plate, dontaining the model number and the fact that it is

12vdc. My simple minded thought is that the battery would simply charge in less time if I set the transformer on 300mA. I even have another charger which supplies 700mA.

Is there any danger of damaging the battery from using a trickle charge that is less/more than what's recommended?

digger

Reply to
charlie

Even with a 12v battery operated device there is no guarantee that the charging brick is DC. I have seen Black & Decker cordless Ni-Cad devices that will use AC bricks and have the rectifiers on board the device instead of being in the charging brick.

If you don't know if the brick is AC or DC then purchase a new one:

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Reply to
tnom

Why not buy a volt-ohmeter (multi-meter) for 5 to 20 dollars and find out if the transformer-device is AC or DC? Then he'll have a meter, if he doesn't have one already.

Reply to
mm

You have a transformer with a 100ma and 300ma setting? Are you sure both settings are at 12volts?

Reply to
tnom

Both my substitute transformers will output 12vdc -- one is variable ranging from 3vdc to 12vdc with a choice of two Ma settings -- 100Ma/

300Ma. The second transformer has a single setting at 12 vdc and 700 mA. These voltages have also been confirmed on my volt meter; needed also to verify polarity.

Thanks, anyone and everyone, for your suggestions.

digger

Reply to
digger odell

Larger amps is more likely to damage. Smaller amps just means longer charge time.

Reply to
Stormin Mormon

My understanding is that too low is no big deal. Too high can "boil" the moisture out of the batteries.

Where did you learn this wisdom? If I'm wrong, I'd sure like to get the correct facts.

Reply to
Stormin Mormon

I found the transformer listed on B&D's web but NO specs. Sounds like the transformer wires would simply heat up if amperage was too low so I could simply switch to to the higher mA setting????

Reply to
digger odell

12v nicad is not 12v. A 1.2v Nicad is dead at 1.2v and charged at near 1.35v. They have an amp rating and you must meet it to fully charge. A C cell might be 1.2-1.8a so 10 C cells could use a 14v 2a charger that senses peak voltage to shut off, you can measure peak V by voltage drop with a digital battery meter, its is also when batteries start to heat up converting electrical energy to mechanical vibrating and cooking the battery to death. Or go see what is sold or call a repair center.
Reply to
ransley

I'm a little bewildered by saying that a 12v nicad is not 12v in view of the fact that the sweeper requires 12vdc to operate.

But I gather from what you say that an under-supply of amps (e.g.

100mA) would not allow the unit to fully charge and no voltage drop would occur. An over-supply, on the other hand, would cook the battery before any voltage drop would occur.

Out of curiosity, would the same be true for a transformer which only supplied 10 vdc rather than 12vdc to the 12vdc rechargeable battery?

digger

Reply to
digger odell

you're mistaking what it can provide vs what it is asked to provide by the load placed upon it.

if a charging circuit attempts to draw too much current from the transformer, and the transformer has no over temp or over draw circuitry (i haven't seen a transformer ever have a fuse), then the transformer will overheat.

the transformer doesn't provide 600ma all the time; that's just how much CAN be drawn out safely. drawing less is not a problem. attempting to draw out

700ma out of a 600ma transformer will cause a fire eventually.

if the load only needs 300ma, then you could provide a transformer that CAN provide 10amp (which would be pretty big), but the load will only pull what it needs, which would be 300ma, which would be safe.

Reply to
charlie

Ahah! Now for the second part of that question ... Adequate amps but slightly under the 12 vdc .... say 1.0 Amp and 10 vollts out on the transformer???

Reply to
digger odell

Ahah! Now for the second part of that question ... Adequate amps but slightly under the 12 vdc .... say 1.0 Amp and 10 vollts out on the transformer???

Reply to
charlie

o high.

A 12v car battery is 100% charged at about 12.8v, and near dead at

12v, but needs 13.3 to saturate cells on your 12v car, its the same with alot af batteries, each nicad needs 13+v to be fully charged, 10v wont do anything as at 12v its nearly dead and fully discharged, a low amp charger will just take alot longer but you need volts 14 is good.
Reply to
ransley

Remember that I'm only using the transformer to recharge the battery in the sweeper; so it gets disconnected when using the sweeper. The only load would be on the battery. And the only question is whether a

10 vdc transformer would adequately recharge the 12 v battery (assuming the amps are OK).
Reply to
digger odell

Remember that I'm only using the transformer to recharge the battery in the sweeper; so it gets disconnected when using the sweeper. The only load would be on the battery. And the only question is whether a

10 vdc transformer would adequately recharge the 12 v battery (assuming the amps are OK).
Reply to
charlie

.
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would you use a 10v charger on a car battery.

Reply to
ransley

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