Tail Servo voltage regulator

[zsultan]

Hi,

I am using 5.1V Two-way Step-down Voltage Regulator K10381A for 9257 tail servo on my T500 to step down the voltage from 6V to 5.1V.

I measured the output of the voltage regulator with a multimeter and it shows 5.72V. Doesnt it have to be 5.1V instead of 5.72V?

Please advise.

Thanks

[thescrivs]

It shouldn't be a problem as the voltage will drop under load.

[chichiuno]

Hi,

I am using 5.1V Two-way Step-down Voltage Regulator K10381A for 9257 tail servo on my T500 to step down the voltage from 6V to 5.1V.

I measured the output of the voltage regulator with a multimeter and it shows 5.72V. Doesnt it have to be 5.1V instead of 5.72V?

Please advise.

Thanks


What you measured and what you should of expected, is correct.
Align should of used at least 2-3 diodes in a series to get the voltage down to 5.1v.

[zsultan]

So, is it OK to use 9257 on 5.72V? Or is it a time bomb waiting to explode?

Thanks

[psindrup]

What you measured and what you should of expected, is correct.
Align should of used at least 2-3 diodes in a series to get the voltage down to 5.1v.

Not so. A diode "eats" 0,7 volts, but only under load.

So, is it OK to use 9257 on 5.72V? Or is it a time bomb waiting to explode?

The servo is not running 5,72 volts.

Try to measure the voltage while the servo is connected to the output side of the step-down, and you will see.

Peter

[chichiuno]

V,

Here is more info the stepdown, that I should of included in my first post:

The diode stepdown, such as Aligns, will drop the voltage aprox, about .5-.6 volts depending on servo idle current.

This is not 5.1 volts Align claims.

The REAL KICKER IS:

You can DROP as much as 1 Volt ADDITIONAL to the .5 to .6 volts the diode gives you, when the Servo is under high loadings.

So instead of having "rock steady" 5.1 volts feeding your HP tail servo, you will have various "rubber band" voltages, serverly impairing the performance of your gyro/servo setup.

Without the step down, your voltage drop will be about .1 volt at a full stall conditon of the servo. (all measurents may vary, dependent on servo/battery combinations)

I use the 9257 on my 500 at 6 volts, with no problems.
When I use the step down, tail performance goes out the window.


When I installed the new plastic Align blades, which are larger than the black stock ones, I swaped out the 9257 to a standard size servo, the JR DS8900, running 6 volts, with no problems.

A couple other tips:

A) Use the aluminum hex nuts in the boom clamp instead of the plastic ones.

B) Get a sheet of 600 grit sand paper and a flat surface like a glass table.
lay the sand paper on the glass table, then take the boom blocks and carefully sand the mating faces of the blocks till you see no shiney spots left on the mating surfaces.
beware the mating sufaces of the block that would protrude past the rear of the frames (where the 3m bolts are located) are faced on a slightly different angle, so you would have to reposition (re-angle) the blocks to reface the mating surfaces on that part of the blocks.


Regards
ChiChi

[Finless]

Yep this is true... You cant expect a diode to be a REAL regulator. But a dioide has been used like this for years by Duralite for stepping down the voltage to a tail servo. Nothing wrong with it. Pilots flying 90 sized helis with 611 gyros and 9256 servo (that MUST not be run at 6V) have been using this system for years. Never heard anyone complain before. My Vibe 90 was set up this way as well and worked flawlessly.

I too use a 9257 and I have the step down diode and do not have any tail control issues. I have seen more than one 9257 burn out running straight 6V when flown hard and this was on a little Trex450. OICU812 can support that as well as he has had 9257's fail at 6V as well.

I personally would not risk running the 9257 on 6V since I personally have seen them go out. Use the drop down on the tail servo. It will be fine.

Bob

[chichiuno]

Yep this is true... You cant expect a diode to be a REAL regulator. But a dioide has been used like this for years by Duralite for stepping down the voltage to a tail servo. Nothing wrong with it. Pilots flying 90 sized helis with 611 gyros and 9256 servo (that MUST not be run at 6V) have been using this system for years. Never heard anyone complain before. My Vibe 90 was set up this way as well and worked flawlessly.

I too use a 9257 and I have the step down diode and do not have any tail control issues. I have seen more than one 9257 burn out running straight 6V when flown hard and this was on a little Trex450. OICU812 can support that as well as he has had 9257's fail at 6V as well.

I personally would not risk running the 9257 on 6V since I personally have seen them go out. Use the drop down on the tail servo. It will be fine.

Bob


Bob,

In a world of compromise, I don't.;)

On your 600n, rip out that diode and drop in a Reactor X, and you see what I am talking about.

[psindrup]

Bob,

In a world of compromise, I don't.;)


Sorry, but you don't what? :thinking

T.i.a.

Peter