Pellott

Recently I bought an MT-4.

I'm very happy with it, but there is this one thing. The telemetry receiver that I got is the rx-461. Since I only use electric cars the telemetry will only show the voltage of the BEC in my ESC. It is possible to buy the rx-462 receiver which has an external voltage sensor. That would allow me to get the voltage of my main battery instead, but it is quiet expensive.

When looking at pictures the two receivers seem to be very similar. I wonder if the rx-461 and rx-462 receivers actually are the same, but with a different wiring. I'm thinking that perhaps it is even possible to modify my 461 into a 462 receiver.

Does anybody else have similar thoughts?

Pellott

Following up on my own post...

I took a few pictures of the rx-461 receiver circuit board. If someone have similar pictures of a 462 it would be possible to see how the external sensor is connected.

I don't have permission to post links to the pictures since I'm a new member here. But I've uploaded the pictures to an album in my profile.

Also, I learnt that there is a resistor on the external wire of the 462. Does anybody know how many ohms it has?

ufoDziner

iTrader: (39)

I have a 462 at home that I can snap some shots of.

If I recall correctly, it's a diode, but it's been a while since mine got damaged. I'll see if I can find it.

Pellott

I would really appreciate if you could! In particular (of course) it would be nice to see where the extra wire goes. As you can see on my pictures there is an extra port which is hidden when the cover is on. I suspect it has something to do with the extra wire. But I'm not sure it is as simple as that. I believe there is some thing else that differs as well, which cause the the receiver to sense the voltage on the wire, rather than on the channel-connectors.

I just assumed it was a resistor, but it could of course be a diode. Does it say in the documentation?

ufoDziner

iTrader: (39)

Sorry it took a couple of days, but here are the pics. First is of the rx-462, and the second is of the broken part. If you can't read the label, it says 1/8 a LF.

Pellott

Great! Thanks for helping out!

Comparing with my own pictures, it's easy to see where the wire should go. But there are small differences in the copper tracks close to the "connection".

Hmm, the labeling on the part makes me confused. It doesn't look like a resistor, they usually have color codes. Diods usually have a single band on one side. What is it?

Unfortunatelly I'm working late tonight, and I'm in a different timezone (sitting in Sweden), so it's gonna take a couple of days untill I get an opportunity to experiment a little with this. But I'll report back when I get the chance.

Pellott

Did some experiments with this just now.

I've opened the receiver and connected a regular receiver-battery to one of the channel connectors. The display of the transmitter will show the voltage at the receiver as usual, just above 5V.

I then connected the negative terminal of the receiver battery with the negative pole of a lipo battery. Then I connected the positive terminal of the lipo to the "connection-point" on the receiver board.

And nothing... The readings on the transmitter display shows 5V still. I've looked closely at the board for clues, but I have now ran out of ideas.

Well, I gave it a try, but I'm giving up on this. At least for now. Anyway, thanks for helping out.

ufoDziner

iTrader: (39)

I might be able to open a 461 up side by side with my 462 this weekend. If I'm able to and find anything out, I'll let you know.

whitrzac

iTrader: (97)

1/8 amp
Lead free

Pellott

Thanks!

Pellott

OK, make sense.

So, is it a resistor that will limit the current to 1/8 ampere? I thought that resistors let through different currents depending on the voltage you put on it. Are there perhaps different kinds of resistors?

Or is a limited current a property of a diode?

OM2KW

according to user manual it is not resistor but it is fuse.
Looks like this is that part
http://sk.farnell.com/littelfuse/025...5ma/dp/9921940

SpeedHub

iTrader: (1)

Hey guys, Pellot!

I don't feel like spending $90+ on a receiver to get voltage of my drive pack as well, where you able to get all working with RX-461 showing Drive LiPo voltage?

Regards,
Andrew

simonseize

iTrader: (9)

I just use my main pack to power the Rx, and pulled the red wire from the ESC leading into the Rx. This gives me a readout on screen of battery voltage. And if my servo dies a young death, I'll replace w/ an HV servo.

My ? Is, can i do this w/ any Rx and the mt-4? Or just a telemetry Rx?

Pellott

I gave up. You can read more about my efforts on another forum. It is in Swedish so I guess you'll have to use Google Translate or something similar:
http://rsb.se/arena/showthread.php?7...61-till-rx-462

If someone else is able to do this I'd still be interested to hear about it!