Voltage directly to receiver?
 

This is for a gas powered heavy vehicle requiring two "giant" scale 343 oz servo's for steering and a 150ish oz for throttle.

Since there is no ESC to limit power going into the receiver. Will it be ok to directly connect a 9.6 volt pack directly to a receiver to power throttle and dual steering servos?

Servo's say 6.0 volts, but they'll be regulated through the receiver correct? And the receiver will regulate it's power received down to it's working voltage without frying anything?

Will this work, or do I need to regulate it before going into the receiver? Or will I still have decent run times on a normal 6.0 volt receiver battery? Figured 9.6 regulated down would last much longer and keep optimum voltage longer to insure best steering output. I am clueless when it comes to these types of electronics.

Should add it's a Spektrum SR3000 Rx, rated at 9.6v?

Re: Voltage directly to receiver?
 

You need a BEC to regulate the voltage before the RX or you'll probably fry the servos. I'd probably use a Castle Pro BEC or even 3 of the 10 amp little blue guys.

~Chip

Re: Voltage directly to receiver?
 

My personal take is to not subject the RX to high amp draw from the servos, Connect the external BEC directly to the servo.

Re: Voltage directly to receiver?
 

So I would be better off regulating the 9.6 down instead of running the normal 6.0 volt receiver batteries?

Re: Voltage directly to receiver?
 

What radio equipment are you running? I run servos similar in torque to yours in my 1/5. I use a single Life (6.6v) battery plugged directly to the Rx. No problems whatsoever.

Re: Voltage directly to receiver?
 

Spektrum and Hitec, just worried the servo's will drain a 6v battery too fast in a crawler this size.

Re: Voltage directly to receiver?
 

I've read were others have run power directly to the servo
...tapping into the primary battery.

Circumventing the RX's internal voltage supply altogether.

tho' I'm not all that sure how it was done...
or what maximum voltage the servo might accept.
nor what battery voltage/output was utilized.

Possibly a resistor was used in line ? :dunno:

The signal output wire from the RX would still need be wired
to the servo, I'll assume.

Re: Voltage directly to receiver?
 

Then get a softcase 2s lipo...a 5000mah 20C or 30C and run a bec from it to the Rx @ 6v. You could run all day on one charge.

Re: Voltage directly to receiver?
 

Not necessarily looking for a power advantage or anything like that. Not saying that's what that would be. I'm just looking for a way to supply plenty of voltage to the servo's to ensure I get more than 30 minutes of run time out of it without having to stop to charge a battery just to run the servo's.

What about the larger 6v batteries? Like what goes in bump start boxes? Would they be able to plug straight in? Afraid the amps and such from that would be too high, not sure. Size isn't quite an issue, the weight wouldn't be an issue either. But, I'll know more once I get into the build.

Re: Voltage directly to receiver?
 

The RX does NOT regulate voltage, whatever you give it (within the limits of it's spec for input voltage) it will pass on.
Current ESC's have an internal BEC that regulates the power to the RX through the "ESC to RX" cable.

High voltage into the RX can fry parts.
High amp loads out of the RX can burn off traces inside the RX, thus killing it (or killing 1 or more channels).

If it were me, I would use a pack that is more than what I need (2S LiPO is fine) and then run 3 BEC's from it.

One set to 6 volts for the RX.
Two set to 6.5 volts+ to directly feed the servos.

I would guess a 2000mah LiPO pack should run a looonnngggggg time just really feeding 2 servos.

Re: Voltage directly to receiver?
 

He's feeding three...two large scale and one standard. And no esc...running a gas engine.

Re: Voltage directly to receiver?
 

And????

A BEC to the RX should handle the RX and a simple (low torque) servo.;-)

Re: Voltage directly to receiver?
 

Not going to use lipo for this since I have plenty if NIMH, size and weight aren't an issue.

A 9.6v NIMH. 3000+ MAH battery should be more than enough. So one BEC running the two servo's seing as they'll have to run together for the steering. Then another going to the receiver to power it and the throttle servo should be plenty and work well providing more than enough run time than I'd want to run the truck for?