Author Topic: [Charger] Current Limiter  (Read 11980 times)

Offline Just

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[Charger] Current Limiter
« on: February 07, 2013, 06:00:05 PM »
Hi All,

I have 24V 10A charger, but I'd like to limit the charging current to 5A. How could I do so?

Thank you!

Offline Morgen 3Eman

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Re: [Charger] Current Limiter
« Reply #1 on: February 07, 2013, 07:04:17 PM »
Hi Just,

This is going to sound peculiar, but I've used it many times to limit power available to circuits.  Simply put an ordinary household light bulb  (s) in series with the load.  You may have to fiddle around  with some bulb measurements to get the right resistance, about 5 ohms.  They are cheap, rugged and reliable. 

TTFN,
Dennis

Offline Just

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Re: [Charger] Current Limiter
« Reply #2 on: February 08, 2013, 01:29:12 PM »
Simply put an ordinary household light bulb  (s) in series with the load
Probably you intended to wrote "in parallel with the load"?

Offline MAGICPIE3FOCUSPOWER

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Re: [Charger] Current Limiter
« Reply #3 on: February 08, 2013, 01:54:07 PM »
What kind of your charger do you have any pcitures?

Offline Just

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Offline MAGICPIE3FOCUSPOWER

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Re: [Charger] Current Limiter
« Reply #5 on: February 08, 2013, 06:21:58 PM »
Maybe you have some luck.

Open the charger and you will see three trimpots for:

Fan shutdown at prefered current.
Chargingging voltage adjust.
Charging current adjust.

I don't which trimpot  exactly is for every adjustment.
But just play and hook a up multi meter.

Offline Morgen 3Eman

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Re: [Charger] Current Limiter
« Reply #6 on: February 08, 2013, 06:26:32 PM »
By placing the lamps (think very high watt resistor) in series with the load you limit the amount of current available for the load.  Placing it in parallel with the load would just increase the current draw from the supply.

TTFN,
Dennis
 

Offline Just

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Re: [Charger] Current Limiter
« Reply #7 on: February 08, 2013, 06:40:41 PM »
Quote
Maybe you have some luck
Waw! I have a luck! I did not have it already for a long time!

I'll differently try to play with the trimpots! There are exactly three of them there!

Thank you!
« Last Edit: February 08, 2013, 07:01:14 PM by just »

Offline Just

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Re: [Charger] Current Limiter
« Reply #8 on: February 08, 2013, 07:04:18 PM »
Quote
By placing the lamps (think very high watt resistor) in series with the load you limit the amount of current available for the load
What about a voltage drop over the lamp? Will the battery still receive the required charging voltage?

Offline Just

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Re: [Charger] Current Limiter
« Reply #9 on: February 08, 2013, 07:14:24 PM »
Open the charger and you will see three trimpots for:
Fan shutdown at prefered current.
Chargingging voltage adjust.
Charging current adjust.
How could I know how many current I can allow? Originally the charger was 48V 5A. Can I set it for 48V 10A? :-)
While adjusting the trimpot of current limit, how could I know how many I allow?
Thank you!

Offline MAGICPIE3FOCUSPOWER

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Re: [Charger] Current Limiter
« Reply #10 on: February 08, 2013, 07:27:59 PM »
Yes you can adjust the current and voltage.
Only the issue is heat: so be carefull when choosing higher voltage and current.

How do know the current?
Well just hook up the multi meter or amp clamp meter.

Offline Lollandster

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Re: [Charger] Current Limiter
« Reply #11 on: February 09, 2013, 09:37:34 PM »
Quote
By placing the lamps (think very high watt resistor) in series with the load you limit the amount of current available for the load
What about a voltage drop over the lamp? Will the battery still receive the required charging voltage?
As you know the voltage drop is dependent on the current (as stated by ohms law V=R*I). When the charger reaches the Constant Voltage stage the current is so low that the voltage drop over the light bulb will be next to nothing. But playing with the pots sounds like more fun.
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