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Supercapacitor install?

Hello all,

I have three LocoFi 3 modules installed in HO scale locomotives. I am looking to install a supercapacitor based power supply to help maintain operation with dirty track, etc. Has anyone installed a KA/SA such as a TCS KA1/2? Has it worked well? I see in the FAQ section that it is necessary to connect the capacitor in series at the output of a bridge rectifier. Has anyone found a small bridge rectifier that they liked? What did you use? Any information would be great.

Thanks!

Dan

12 comments

12 Comments

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chdiecast

Apr 27

I have tried two different CurrentKeeper caps wired as shown above but each only outputs 4.9 volts when the track power is shut off. Increasing the "charging" time from the tracks does not increase the voltage. Can anyone share their experiences?

chdiecast

May 13

Replying to

I now have the power supply and multimeter — great recommendation! Here are new test results using them.

Test 1: ...disconnect the LocoFi module and charge the CurrentKeeper by connecting to track power. Once it is charged fully, disconnect the track power as well and measure the voltage.

CurrentKeeper A: 14.1 V track power;

12.5 to 12.93 V at the CK while charging 5+ minutes

9.6 dropping to 9.2 V when track power was disconnected.

CurrentKeeper B: 14.1 V track power;

12.63 slowly drops to 12.59V at the CK while charging 5+ minutes

0.3 V when track power was disconnected.

Test 2: ...record the average current consumption of the locomotive when running at average speeds.

CurrentKeeper A: 14.0 V track power;

1/2 throttle: Approx. 300 mA (meter wouldn't settle on a figure).

CurentKeeper B not tested (appears to not hold a charge).

Test 3: Practical test. 14.0 V track power, CurrentKeeper A connected, loco is running on rollers controlled by LocoFi at 1/2 throttle.

11.3 V at the CK while charging 5+ minutes;

Track power off: 4.5 V (LocoFi disconnects from wifi)

2nd test as above except that the track power is quickly switched off then on (about 1/4 second off): 8.0 V (LocoFi stays on and allows control of the loco).

chdiecast

May 13

Replying to

Done. See new test results using the recommended power supply and multimeter.
"Amp rating is based on the decoder’s motor stall current rating. The caps will discharge immediately as needed, so as long as you do not stall your motor more than what the decoder is rated for, then your variable will be the hold up time.." from the manufacturer. The motor is a Mashima can motor but I don't know the model number or spec. I don't want to risk damaging my gearbox/connector parts by doing a stall test.
"The caps are rated at 13.5v collectively, but we do have a voltage regulator to help the caps from being overcharged." from the manufacturer.

Edited

Admin

May 16

Replying to

Hello,

Thank you so much for running the tests. It helps clear things up a lot.

Test 1: With LocoFi disconnected, there is no reason for the voltage to drop as soon as the track power is disconnected. The voltage should have held exactly at the same level the CurrenKeeper was charged to. It appears to be faulty. Do you have another (new) lying around to compare?

Test 2: Very much in line with the expectations.

Test 3: Proves the above two.

Unfortunately, at this point, all we can suggest is to try with a brand new supercapacitor based solution and see if that helps.

P.S. The motor is just fine.

Best regards,

LocoFi Team