bmwcars,
the values of C1,C2 are in the parts list ,the transistor type is also listed go back and have another look .save the webpage for reference .
You may have either your voltage reg or a transistor wired up wrong .
Stewart

First things to check:

Did you mount the 317 right ?
Are the transistors mounted right, check check triple check these
Route all connections and check them one by one. If none of the components is faulty and everthing above is checked this charger should work right away.

regards,

Franck

Can i use a volte meter to measure C1 C2?

Thanks

Course,

Make sure you connect the meter right.

Post the results (voltage) meaured on various points and put them online. (in reference to gnd or -V should be best) That gives us some reference solving your problem with this charger.

Regards,

FRanck

The charger of E-Tec80 exclusive use was made using IC of Linear Technology. Used IC is LTC4054L-4.2. Charge current is 90mA. Charge current can be adjusted from 10mA to 150mA by changing resistance. Resistance of 1.69Kohm is used in 90mA charge. It will OK, if it changes into 3.34Kohm when charging the battery of 45mAh. When charging the battery of 140mAh, resistance of 1.07Kohm is used.

Koichi

He can buy LTC4054L-4.2 with 1 piece $1.66 from Linear Technology.

Originally posted by Koichi Tanaka
He can buy LTC4054L-4.2 with 1 piece $1.66 from Linear Technology.

Now I'm intrested!!

Here's a link for those too lazy to use google:

http://www.linear.com/prod/datasheet.html?datasheet=992

Koichi now that is the simplest lipoly charger yet.
Really nice.

Will the LTC4054L-4.2 charge multi cell packs with
increased input voltage?

If not then you could use 2 for 2 cell packs.

Would be nice to build a charger to charge the 20maH 40maH 90maH 145maH and maybe a bigger one and the dual lipoly pack you use for the IR TX.
This would is all the batteries I use for micro planes.
I do have my SH designs charger built to charge the 40mah , 90maH and 145maH.

The LT IC will make giving away planes with chargers much easier.

Billy

Hi!

In the L200 charger design posted by AndyOne way way back in this thread 'R1' is a 2K2 resistor.

The L200 datasheets says it should be a 500-1K5 resistor.

Is there any particular reason for using 2K2 ???


(-8 Celcius today, no wind yet but on the other hand not much light either as the sun hasn't come up yet at 8:50 in the morning... Full moon though to the right outside my office window.)

Billy,

LTC 1732-8.4 of exclusive use for 2 cells has come out of LT. However, a circuit becomes somewhat complicated.

Koichi

maosl,
In that circuit, R1 along with the pot R2 just forms a divider to set the output voltage. He probably selected that resistor so that the adjustment range would be optimal. The value is not critical, as long as you have enough adjustment to set the output voltage to the proper value.

Jeff

Jeff,


You could be right. Its just that almost every example in the datasheets show a 820 ohm resistor in series with a 3K3-10K pot.

My calculations for a singe cell charger points to a 820 ohm resistor and then a 100 ohm pot + a 350 ohm resistor for about a 4.0 to 4.3 V adjustable output.

As this is 10 times less than the resistors suggested by AndyOne I was thinking he might know something that I'm unaware of...

/Martin

To add to Jeff’s comment: the important point about the two resistors is that they divide the required output voltage down to a value of 2.77V. The value of 2.2k was chosen for R1 by experiment but a lower value of around 1.8k is required to get a reliable 12.6V output when using a 10k pot for adjustment. Any two values (within reason) that form the correct division ratio will work.
Maosl, using a low value pot in series with a fixed resistor will give you a fine control over your voltage setting which means you may even get away with using a single turn pot but I just used unsubtle approach of a multi-turn pot. I used 10k because it’s what I had to hand.

I have recently put it all onto a PCB, which allows the selection of 3 currents and 3 voltages I will post details soon.

The values that allow me to get the correct charging voltages for 1, 2 and 3 cells (4.20, 8.40 and 12.60V respectively) are two 10k pots one 50k pot with R1 at 1.8k.

Andy.

Martin,
Even if you use precision resistors, you may need to build in more range than that. Using 5% resistors, the divider could be off by up to 10%. I haven't looked at the spec sheet for the regulator, but I bet the tolerance for the 2.77 volts at the center of the divider is maybe 2% possibly even 5%. The total error could be +/- 0.4 volts or more. It is no problem if you can hand select the components, but to guarantee that it will work with parts at the edge of their tolerance, you will need more range on your pot.

Jeff

The total tolerance range of the reference in the L200 is stated at 2.64V to 2.86V which works out to about -5% and +3%.

Andy.