Getting tired of replacing batteries in some appliances. How do I calculate what capacity (mA) power supply I need.
I have 4 C batteries in series to it is 6v. however how many mA do I need to shoot for?
2007-08-14 15:28:36 · 7 answers · asked by charlie 1 in Science & Mathematics ➔ Engineering
You can get a transformer (which is dangerous if you are not familiar with them) or a voltage converter....you can get those at Radio Shack.
2007-08-14 15:37:58 · answer #1 · answered by Wayne L 2 · 0⤊ 1⤋
From the graphs on the energizer battery site, C batteries are typically used in applications that draw 300-700 mA of current. When you buy a power supply, what's on the supply is a MAXIMUM current rating...so as long as you buy a 6 V supply with a rating of 700 mA or more, you should be OK.
2007-08-14 16:24:51 · answer #2 · answered by Anonymous · 1⤊ 0⤋
Your replacing C cells with a small transformer. Let drop the amp problem and go with watts for a second. Most batteries are rated in Ah (amp hour) but small C cells are not under a static load of 15watts they will perform for 2 hours since
P(watts)= I(amps) x E(volts) we can find I by dividing 15 by 1.5= 10amps . This calculation though in itself does nothing since the actual load on the battery is unknown. So Lets look at the process under a full load the batteries will in series give you 6 volts at 10 amps for 4 days . Or it will give you 6 volts at 1 amp for 40 days or 6volts at .1 amp for 400 days. Not knowing your objective, reverse design for actual usage and i would expect an average of 800mA as the proper size for the transformer. Observe polarity when installing.....Good luck from the E....
2007-08-14 16:11:31 · answer #3 · answered by Edesigner 6 · 0⤊ 1⤋
The important thing is the voltage rating of the converter it should match with the required as you mentioned its 6V. But the converter current capacity could be able to give the required as per the load is needed. Remember that the load current will only dependent on the load resistance.
2007-08-14 16:51:20 · answer #4 · answered by dongskie mcmelenccx 3 · 0⤊ 1⤋
That depends on the mA that the device is drawing. Most battery powered devices do not say so that is a major problem.
How about getting rechargeable C cells instead? Then it will not make any difference because the cells will recharge and discharge as needed.
2007-08-14 15:34:02 · answer #5 · answered by Rich Z 7 · 0⤊ 1⤋
read the current rating off of the back of the device. that will be at operating voltage. then P in watts = I in amps X E in volts....won't hurt to over size it so you don't have to worry about it
2007-08-14 16:41:11 · answer #6 · answered by ELEcTrIc_HeD 3 · 0⤊ 1⤋
AA I have a battery recharger for my AAA and AA but have not gotten the rechargable AA yet. Keep forgetting. (((Frijid)))
2016-05-18 00:30:06 · answer #7 · answered by ? 3 · 0⤊ 0⤋