noticed something interesting while switching pcb boards

[spikeymike218]

i just recently bought a microsizer sport to replace my old bit char-g since it was out of commission(part where engine cover clips onto broke, axle doesn't stay in).

well the reason for this transplant was that the range with the microsizer was worse than my bit char-g(this is a 27mhz). so what i did was transplant my old bit char-g pcb board over to the new microsizer chasis.

during this swap, i noticed something different between the two boards when comparing

1st: on the microszier: under the pcb board where the wires are soldered onto, there is a blue wire going to the F, and a white wire going to the B. heres the strange part, in between the two solders(F & B) was a piece of metal connecting them together. i looked at the bit char-g board and nothing was between the F and B.

2nd: also on the underside, the cylinder shape thing(i'm guessing its a capacitor), on the mircosizer it says 85 C, while the bit char-g says 105 C. strange.

just wondering if anyone has noticed these differences between the microsizer board and bit char-g.

well onto the swap, soldering the wires wasn't as bad as i thought it would. to sum things up, the sway was successful and the range was back to what i had normally with my old bit char-g.

[Nathan]

Tomy has several different board revisions. The MS sport is probably newer.

[spikeymike218]

actually, they were both Rev 5 boards.

[mjb]

Originally posted by spikeymike218
heres the strange part, in between the two solders(F & B) was a piece of metal connecting them together. i looked at the bit char-g board and nothing was between the F and B.

This will be a noise suppression capacitor across the motor, so that the motor running doesn't trash the receiver sensitivity. Not all bits have this. It might look like a bit of metal, but there is a "chip style" capacitor in there somewhere.

2nd: also on the underside, the cylinder shape thing(i'm guessing its a capacitor), on the mircosizer it says 85 C, while the bit char-g says 105 C. strange.

It's a capacitor, used in the voltage doubler circuit-- it gets you the 3v to run the rx chip. 85'c or 105'c, is just the temperature rating, don't worry about this.

[Namuna]

Some good info there mjb, thanks.

[funkymonkey]

mjb, good info - Ive pondered about that voltage double before though. If it pumps 3V to the RX chip, what about when you have dual or triple cell? Does it regulate it to 3V or will it keep doubling? Cos surely this would mean a triple cell would kill the RX2C, yet this doesnt seem to happen.

Also, someone else might have asked it, but anyone know a rough idea of motor life when its running at 2.4V or 3.6V? I imagine the motor's life is reduced quite significantly?

Anyone know the stock life on these motors while we're at it?

[hogjowlz]

my best motor is from a "thor" clone that was a pos. this motor has ran almost daily since say october and hasnt flinched. it really likes dual batteries. but ive only been running dual batteries for a few days so who knows.

[mjb]

Originally posted by funkymonkey
If it pumps 3V to the RX chip, what about when you have dual or triple cell? Does it regulate it to 3V or will it keep doubling? Cos surely this would mean a triple cell would kill the RX2C, yet this doesnt seem to happen.

It's a doubler when used "as intended". What seems to happen is that putting a 2nd cell on boosts the voltage a little: e.g. 2.97 to 3.1 v. It doesn't get too high for the chip, which is probably the reason why everyone is getting away with sticking more and more cells on

Motor life :- I've seen 100 hours quoted, but I think that's from misreading the manufacturer's test spec. What they say is that the motor lifetime test is 100 hours. After that, the motor must still perform within the specs. This means it could die at 101 hours, as a sudden failure, or it could go on to 200 hours, degrading slightly ... before failing even later.

They do say this is for running the motor "the right way" (brush wear etc.), this is with the shaft turning clockwise as seen end on. This means that (as bits have a 2 stage gear reduction) the rear wheel turns clockwise for correct running, which corresponds with reverse So there is some life reduction there, but are you really worried about that when you've got 2 or more cells powering it !

Mike.