Hey guys
I was planning in using the MAX712 chip to charge a 9.6v 2500mah NiMH battery pack. After reading through the datasheet a few times, this is what ive come up with.
I wanted to use a laptop power supply for power (**broken link removed**)
I wanted to charge at 1C (2500 milliamps). I dont want to use the temperature sensing feature.
Here is my schematic.
R1 = 2340 ohms (or closest resistor)
Rsense = .1 ohms (ten 1 ohms in parallel?)
**broken link removed**
Here is the datasheet for the chip
http://datasheets.maxim-ic.com/en/ds/MAX712-MAX713.pdf
I have a few questions regarding my circuit:
1) I notice the diode used in the Typical Operating Circuit is a 1N4001. Digikey says this can handle up to 1 amp. Since I want to charge at 2.5 amps, this is a problem, right? I was looking around on Digikey and i found this beast (Digi-Key - 641-1317-1-ND (Manufacturer - 6A4-G)). Supposedly it can handle 6 amps, with almost every other detail the same as the 1N4001. Would this be a good substitute? I get the sense that this isnt necessary, since this diode is huge, and it looks like one of those super specialized things. 6 amps isnt even that much...
2) With the current circuit, the temperature sensing feature wouldnt interfere would it? (keep in mind, i dont want to use it. I want it to essentially be disabled)
3) The LED should go ON when fast charging and OFF when trickle charging. Is that setup correct?
4) Would ceramic capacitors work for C1 and C2?
Finally,
Do you see any problems with this circuit?
Thanks!
I was planning in using the MAX712 chip to charge a 9.6v 2500mah NiMH battery pack. After reading through the datasheet a few times, this is what ive come up with.
I wanted to use a laptop power supply for power (**broken link removed**)
I wanted to charge at 1C (2500 milliamps). I dont want to use the temperature sensing feature.
Here is my schematic.
R1 = 2340 ohms (or closest resistor)
Rsense = .1 ohms (ten 1 ohms in parallel?)
**broken link removed**
Here is the datasheet for the chip
http://datasheets.maxim-ic.com/en/ds/MAX712-MAX713.pdf
I have a few questions regarding my circuit:
1) I notice the diode used in the Typical Operating Circuit is a 1N4001. Digikey says this can handle up to 1 amp. Since I want to charge at 2.5 amps, this is a problem, right? I was looking around on Digikey and i found this beast (Digi-Key - 641-1317-1-ND (Manufacturer - 6A4-G)). Supposedly it can handle 6 amps, with almost every other detail the same as the 1N4001. Would this be a good substitute? I get the sense that this isnt necessary, since this diode is huge, and it looks like one of those super specialized things. 6 amps isnt even that much...
2) With the current circuit, the temperature sensing feature wouldnt interfere would it? (keep in mind, i dont want to use it. I want it to essentially be disabled)
3) The LED should go ON when fast charging and OFF when trickle charging. Is that setup correct?
4) Would ceramic capacitors work for C1 and C2?
Finally,
Do you see any problems with this circuit?
Thanks!
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