heq5 voltage question

[Michael1971]

Hi,

I bought a new power supply since I am diagnosing issues with my heq5 mount.

I got a Tristar kb-7985 12v 5a

If I check on my handset (v3) it shows 20volts, I am wondering if someone could check their voltage the same way to see if this is right or not.

Thank you,

Mike

 

[Robindonne]

The last time i checked mine it said 12 or 12,?? Volt.  If you have a multimeter i’d better check it before you start doing long use with this combo

[Michael1971]

I tried 2 power supplies and both show 20v in the handset.. How odd.. 🤔

[Robindonne]

If you’ve checked the psu with a decent meter I wouldn’t pay much attention to the  skywatcher-meter😬

[jambouk]

Definitely check the output of the power supply with a voltmeter make sure both power supplies are not delivering 20v before using them on the mount. If they are both saying 12v or thereabouts then there is no reason the mount should be stepping up the voltage if it is a standard mount with standard wiring etc. There was a handset firmware update several years ago which resolved an incorrect voltage reading, but I don't think the error was this great, but maybe worth updating the handset firmware.

[Michael1971]

My equipment is on an other location, so Ill check later today with a multimeter and post the results. But I think it must be an error in the handset.

 

[Michael1971]

Ok my trusty multimeter showed 12volts (12,1) so power supply is good.

I red that on some handsets there was a bug that made the voltage information on the handset to high.

Since I had latest version I thought I was ok, but you need to install a firmware fix to fix this anyway.

Install the fix then reload new firmware and now its ok.

Thanks all for responding

Cheers,

Mike

[SimM]

My experience of HEQ5 and EQ6-r Pro (two SW mounts only) is that a multimeter will show the output of a PSU open circuit to be regulated e.g. 12.1v. The HC utility -> information -> voltage will show a lower voltage 0.7v lower (drop across a silicon diode inside the mount?) e.g. 11.4v.

If you used a car adapter you could also measure the voltage on the battery whilst the mount was in use. Again it will show 12.1v at the battery but only 11.4v in the hand controller.

There was a skywatcher fix for the HC voltage readout. So check the firmware and sky watcher website.

If a multimeter shows 20v when a PSU isn’t connected then it indicates the PSU isn’t regulated and should be avoided as a power source for the mount (12v RMS is about 20v max e.g. what the voltage is measured).

Simon

Edited July 5, 2020 by SimM