Power supplies

[Wobbly Bob]

Am I right in thinking that ideally one should have seperate 12/13v for Dew Heaters and another for the mount !.

If this IS the case, then which of these two PS would you use for the above, I have a Maplins PS which I have been using to drive the Mount, I also have a PS from a desk top computor which has a 12v supply. So what would you use to supply the Mount and the Dew Heater ?

[arad85]

One will be fine if it can drive enough current to fully supply both.... I wouldn't use your PC supply to drive the PC, mount and dew heaters in one go - it is likely to not be able to supply enough current

I use a 12V battery with inverter to drive my mount, dew heaters and PC on occasion. OK as long as it's fully charged and I don't need too long out there...

[Wobbly Bob]

Arad, I have mains in the obsy with a surge protected multi socket, so the PC and Maplins PS run from this. It just somewhere from the darkest depths of my memory, i seem to remember someone saying that if you used the same PS for both MOUNT and DEW HEATERS, some thing could go hay wire

[chrisrnuttall]

the frequent switching on and off of the dew controller can cause the voltage to fluctuate on the supply lines. if the mount is a goto then then it has a small processor running it and the fluctuations can make is malfunction if you use the same psu for both items.

i have a goto mount and a dew controller, and i use two batteries, one for each.

Also, you need to check the current ratings of the power supllies - it should be written on the casing for each one. Then if you look up in the mount's manual the amount of current it needs you will know if either is suitable. Likewise for the dew heater strap, the manufactures website should tell you what current it needs to run. If your psu's can't supply enough then you will get poor performance, and the psu's may expire prematurely.

hope this helps.

[arad85]

the frequent switching on and off of the dew controller can cause the voltage to fluctuate on the supply lines. if the mount is a goto then then it has a small processor running it and the fluctuations can make is malfunction if you use the same psu for both items.

And this SHOULD be OK with a single power supply that can supply the current requirements of both... Same with a PC power supply... buy cheap and repent in leisure

[Wobbly Bob]

Thanks Chris, I had a feeling those fluctuations came into the mix some where. I think I will keep the Maplins regulated supply for the Head and use the computor PS for the dew straps, I do have another if the first goes wrong.

[roundycat]

Bob, I think I am in between two schools of thought here. In the first place I don't, and doubt I ever will, find it necessary to have a fancy dew heater controller. Some of the PWM types probably cause noise that you would not want to go back up the line and infect something else. I just use a variable PSU for dew.

Some other types of PSU may have a nominal 12v output but only at a certain value of load current. Hence if you 'overload' the PSU you will not get 12v which would be a problem with the mount.

Dennis

[Wobbly Bob]

Hiya Dennis, I intend to use my trusty Maplins PSU for the mount and try out this computor PSU for the due heaters. The dew heater controller is a very basic affair.

I do remember noting your PSU arrangement, which I think led me to starting this thread in the first place. Though if I remember correctly, your main reason for a seperate supply was for your camera's.

[roundycat]

Hi Bob, It is certainly true that I would never use a camera PSU of any type to run more than just the camera. There is a fighting chance you can run the mount and heaters off the same supply provided you can be sure that fancy dew power controllers won't corrupt the mount in any way. What you are suggesting sounds good to me so long as there are no funny issues with the Computer PSU being unregulated, ie, the output voltage changing as the load current changes. That might give a power controller something to think about. Suck it and see, I can't see anything getting damaged.

Dennis