Electronic advice on power supply, please.

[Lester]

Hi all,

I have just purchased a Dick Smith Laboratory power supply 13.8vDC 23Amp.

I am planning on using it to power my Losmandy Titan mount. On reading the manual, under Caution, I read; Do Not use this power supply for highly inductive loads such as solenoids or motorized equipment, as turn-on surges and back-EMF spikes from these loads may damage components in the power supply.

Would the motors in the Titan mount fall into this catergory?

Thanks.

[rogerco (Roger)]

I am no expert but as a ham radio operator I can tell you that this supply is designed to run high power (100watt) radio transmitters. I doubt that it will even notice your mount motors. The voltage may be a problem if the mount is expecting 12v. But check with the telescope manufacturer. If your motors are stepper motors then you are driving a control circuit which will have fairly tight power supply tolerances.

Roger

[Barrykgerdes]

The power supply should have no trouble with those type of motors as they are fed through some sort of controller that will normally be seen as a resistive load to the P/S. I have been using one of those P/S for a few years now to power a telescope and a 100watt ham rig with no bother. Just don't try to run a 12 volt electric drill!

Barry

[mswhin63 (Malcolm)]

Power supplies especially Lab ones which are regulated are usually affected by back EMF from motors, solenoids and relays. Special power supplied Diode protection or large capactance is usually require when operating mid to large motors.

A battery is a very good capacitor and would protect a power supply although Lab Power supplies a bit overkill.

[mswhin63 (Malcolm)]

I was looking at the information for the controller and the controller has inbuilt regulator so there is generally no need for a lab type power supply. But at the same time it may have it own protection built in which consequentally won't feedback into your power supply.

Should be alright although I have only very quickly looked at it.

http://www.losmandy.com/losmandygoto/gotospecs.html

[Lester]

Thanks for your feed back, Roger, Barry and Malcolm; it all helps to give me peace of mind in an area that I am not fully coherant.

[acropolite (Phil)]

If you're worried about back EMF you can use a reverse biassed Zener diode of a couple of volts higher rating than the voltage you're using.