[intlplby]

ok... i got some problems with the PPA battery board if anyone can help me out...


i have 18 AAA cells at 650mAh each

R1 - 650ohms
R2 - 5 ohms
R3 - 120 ohms
R4 - 120k ohms
R5 - 8.2k ohms
R6 - jumpered
R7 - jumpered
R8 open


i hooked it up and C1 fried (looks black) and i know i had it oriented correctly since it is polarized. There is a funky burnt plastic smell too

the solder joint on the two 10 ohm resistors i had in parallel for R2 cracked.

i don't have a Q1, RLED, or and LED

I am using an LDO circuit

i have one spare C7 left and a spare regulator and one spare charge controller.....

voltage supply is 31.5V

anyone have any ideas on what is wrong?

 

[__redruM]

Quick guess: Are you using 35V Caps? I lot of the caps used in the tangent amps are 25v. As long as you used the part numbers in the parts list, you've got 35V caps.

Also why LDO? If you used the LM317, you wouldn't need a C1 at all.

Last, I tried to enter your numbers in the config calc, and couldn't get your same values. My values were close, but not the same. What did you use?

 

[intlplby]

35v caps in the amp and then all the battery board parts are the same as tangent suggests

i am trying to make fast charge so that's why i used LDO


i used the values in the calculator for 2.5 hours with 18 650mAh cells with an LDO circuit

 

[tangent]

Quote:

i know i had it oriented correctly

Not to second-guess you, but how do you know? Unlike with alum elecs, the + lead is marked on tantalums, not the - lead.

Quote:

all the battery board parts are the same as tangent suggests

Sooo...you're saying you used 25V caps?

Quote:

i am trying to make fast charge so that's why i used LDO

LDO is not necessary for fast charging. It just allows you to get away with a lower supply voltage.

 

[intlplby]

the plus was marked on the little cap and i put it in the square solder pad....



does the full power supply voltage pass through any of the caps on the battery board?


oops i didn't know i could use the LM317 still.... either way i got LM1086 in there.....

either way i got the problem fixed... when i hooked up the connector i accidently switched the wires for B and V+ so instead of it being
V- B V+ it was V- V+ B to the board

now it is all hooked up and nothing is getting hot and it looks like it is trickle charging, but not fast charging (led is not lighting at all)

 

[tangent]

Quote:

does the full power supply voltage pass through any of the caps on the battery board?

Very nearly the full voltage goes through C1.

Quote:

i didn't know i could use the LM317 still....

You'd have to increase your supply voltage to about 34V, of course, and you'll generate more heat, but it can be done.

Quote:

i accidently switched the wires for B and V+

I don't see how that would cause any problems. D2 should have protected the circuit. But given that you killed the caps by reverse voltage (apparently), I'd suspect all the active devices. Replace `em all.

 

[intlplby]

i replaced the charge controller, the two TLE's and LM1086.


hooked it all up and it appears to be trickle charging still and the LED is not on.

i will not the following though..... the voltage about 2 hours ago at R4/R5 was like .55V or so and now after trickle charging some it is at .85V or so and i have never used these rechargeables (brand new) so i think the voltage may still be too depressed for the fast charge circuit to kick in right? i shouldn't be able to see it fast charge until the voltage at R4/R5 goes over 1V, right?

if it does start fast charging, but is trickle charging now why isn't the LED at least lit and steady

RLED is 3.3k and is going to the closest hole, but i jumpered Q1 such that it is as if RLED was going to the hole going to the corner

 

[tangent]

Yes, and all the diodes, including the LED.

 

[intlplby]

i'll have to see if radio shack has those diodes, because i leave for china on thursday morning and unless i overnight parts i can't get stuff from mouser anymore.

i don't have any 1n4001 in the DO-41 package, but i do have a bunch of 1n4004 in the DO-41 package

will those work as well?

 

[Syzygies]

Quote:

Originally Posted by intlplby i don't have any 1n4001 in the DO-41 package, but i do have a bunch of 1n4004 in the DO-41 package will those work as well?

If you check e.g. a datasheet at Mouser, you'll see that the 1N4004 has a higher voltage spec than the 1N4001, and loses nothing in trade. I can't see or measure anything significant lost. I use any diode that's handy and good enough specs.

Why they even bother making the 1N4001 when the series is priced like tap water, perhaps someone can explain to us. You'd think it'd be like single pole switches, where they sell you a double pole switch and tell you to ignore one of the poles. "Here's a 1N4001! If that second 4 bothers you, scratch it out so it looks like a 1!"

 

[@sia@home]

yep they are just speced for a higher voltage across them

should still be fine.

thats the 1n4001 vs 1n4004s btw

 

[tangent]

Quote:

i shouldn't be able to see it fast charge until the voltage at R4/R5 goes over 1V, right?

Yes.

Quote:

RLED is 3.3k and is going to the closest hole

Sorry the docs weren't clear on this point. I've fixed them. See step 5.

 

[intlplby]

i'm still quite confused by step 7..... i put up the voltmeter at the one of the legs of either R4 or R5 on the size closest to the board and at V- (the pin closest to the batteries), right?

when i do that i get 4.22V... what do i need to change?

oh yeah and no parts get hot... not the charge controller or the regulator or anything at all


edit: update... as the board stays plugged in the value of R4/R5 has dropped from 4.22 to about 4 in the last 40 minutes

 

[intlplby]

R4/R5 to V- is 3.9V now

....... i noticed something though...... when measure voltage from the first and last batteries with the amp on it is like .7V, but if the amp is on and i power it off it very quickly climbs to about 9-10V but the moment the amp is turned on again it drops to .7 V

a similiar thing happens at R4/R5 and V1.....when measure voltage it is like .7V, but if the amp is on and i power it off it very quickly climbs to about 3.9V now but the moment the amp is turned on again it drops to .7 V

every active component has been replaced and i put a new set of batteries in as well

 

[intlplby]

ok.... confirmation that the circuit is trickle charging the batteries, but very very very slowly..... since last night (almost 19 hours ago) the circuit has brought each cell from .05V each to .5 volts each.......


do i need to basically justy leave it connected until it finally reaches a normal range or is there some way to speed this process up? what resistors do i change? R1 right?

it's like 650 now.... i can change it to like 510 or maybe a bit lower, just not below 430, right?