What's the output signal from an Rx?

[clockworks]

I'm working on a non-RC project that needs an ESC and LiPo pack to run a motor at a fixed speed. Is there a way to simulate the output from a receiver?
I've no idea whether the Rx just outputs a variable voltage or some kind of modulated signal.
Does anyone know?

[constantmotion]

Radios produce a variable signal to the receiver. If you want your motor to run at a constant speeds the a ESC (Electronic Speed Control) isn't needed. You might want to find some mechanical speed control and hook it up a some kind of knob. They only have a few contact points to adjust output to the motor.

[Narly1]

Here's a selection of motor controllers that work off of an analog input:

http://www.robotshop.ca/analog-motor-controllers-2.html


Narly1

[clockworks]

Wow, that robot gear's expensive!

I managed to find out, like constantmotion said, that Rxs use PWM to control ESCs and servos - not a simple voltage level.

I was planning to use a 2s 200mAH lipo to power a pace car for our 65' oval slotcar track. One of the club members thought that it would add a touch of realism to our NASCAR races.
Thing is, the pace car needs 6.5v to circulate at a good speed, without crashing. I need a way to get a constant 6.5v at 1A from a 2s LiPo, and the circuit must be small and light enough to fit in a 1/32 slotcar.
A small airplane ESC would fit, but I'd need another circuit to generate the PWM signal.
Maybe a voltage regulator would be simpler, if I can find a 6.5v circuit.

[Almighty Malach]

Try a Castle BEC. They are good to 7 amps and 25 volts and you can set the voltage to whatever you need. It'd be nice and small too

[clockworks]

I have thought of using a BEC, or maybe one the regulators that are starting to appear for the nitro and plane boys. They allow the Rx to be run from a 2s lipo.

I've actually had a CC BEC on order for a few weeks now. There's no stock in the UK, as Castle are changing to a new UK distributor. The BEC is seen as a low priority item, so none have been imported for a while now.

Does anybody else make a decent, adjustable, BEC? I need one for my crawler.
Alternatively, are there any US sellers that will post a CC BEC and castle link to the UK without charging silly prices for shipping? One place that's recommended here wants $20 shipping, but the USPS only charges about $6.

[JohnRobHolmes]

You can get it slow shipped for just a few bucks, yep. Flat rate priority is $18 and EMS is almost $30 now.


I could slow ship it if your UK supplier won't have stock for a while.


I was going to suggest the BEC as your best bet. Otherwise you need a PWM circuit and speed controller, and you don't need all that.

[clockworks]

Originally Posted by JohnRobHolmes

You can get it slow shipped for just a few bucks, yep. Flat rate priority is $18 and EMS is almost $30 now.


I could slow ship it if your UK supplier won't have stock for a while.


I was going to suggest the BEC as your best bet. Otherwise you need a PWM circuit and speed controller, and you don't need all that.

Hi

Thanks for the offer. I tried to PM you, but couldn't.
I'd like to order a CC BEC and Castlelink, shipped by normal USPS.

Could you ship them separately (2 parcels)? If the goods plus shipping goes over £18 ($29), we have to pay import tax plus an £8 ($13) handling charge. 2 separate parcels avoids this.

[JohnRobHolmes]

send me an email or just go to my site and place the order.