AC Adapter amperage

[flinx]

Re: AC Adapter amperage

16V about 5A feeding bridge rectifier with about 10,000 uF to supply surge current.

I located a transformer from an old APC UPS. The output from it is 16.25 volts AC, Once ran through the Rectifier the voltage is now about 15.25 DC. I have not found a 10000uf cap. Any Ideas where I might scrounge one? I do have several 3300uf 16v caps I can run in parallel.

[budm]

Re: AC Adapter amperage

16V about 5A feeding bridge rectifier with about 10,000 uF to supply surge current.

[flinx]

Re: AC Adapter amperage

sigh™ OK, so my options are:
Purchase a battery pack $61.00
rebuild the battery pack $39.00
Build a power supply from scrounged parts $??

I have 2 or 3 full wave bridge rectifiers (unknown specs).
A large collection of various capacitors (from badcaps.net.
The thing I need is a decent transformer. I have a small collection. What size transformer would I need to get a dc output of 21-22 volts?

[budm]

Re: AC Adapter amperage

Start-up and Stalled current of motor can be as high as 20 to 40 times running current, switch mode power supply is not made for high in-rush current, especially the laptop one, it will trip the over current protection circuits.

[flinx]

Re: AC Adapter amperage

Doesn't matter how many amp hours the battery has, it could potentially provide a lot more than 7.1 amps. Also, the stall or startup current of that motor is likely very high; you may be able to get it to run better by giving it a little push.

Hmm... well it does turn by itself but in a pulsing way. About a tenth of a turn every half second (give or take).

[tom66]

Re: AC Adapter amperage

Doesn't matter how many amp hours the battery has, it could potentially provide a lot more than 7.1 amps. Also, the stall or startup current of that motor is likely very high; you may be able to get it to run better by giving it a little push.

[flinx]

I have a nicd powered 18 volt pipe cutter. I found it in the street one day (in its box with 2 batts and a charger) and though I do not have much use for it, I do use it occasionally. However the batteries died and I did not want to spend the money to get new batteries for something that I hardly use. So I decided to hard wire it.

I have a PILE of AC adapters and found one for an HP laptop that is 19 volts and (supposedly) 7.1 amps. However when I hard wired it to the pipe cutter it barely could move it and the light would go out on the AC adapter. Is this because it is not running at 21.75 volts that a fully charged battery pack puts out? or is the AC adapter lying about its amp rating?

correct me if I am wrong but most nicd battery packs are are only around 1.3 to 2.2 amp hours.