DC circuit protection for HEQ5 - needed?

[GTom]

I am experimenting with a custom TEC cooling and a bit worried about my mount electronics. The Peltiers will operate at ~14V, so far the plan is just to hook them up on the same splitter where the HEQ5 is connected. Can I go wrong with that?

[Albir phil]

37 minutes ago, GTom said:

I am experimenting with a custom TEC cooling and a bit worried about my mount electronics. The Peltiers will operate at ~14V, so far the plan is just to hook them up on the same splitter where the HEQ5 is connected. Can I go wrong with that?

I have a cooler for my DSLR which I only use with separate power supply.

[Dr_Ju_ju]

Personally, I'd drop the 14v down to 12v using either a regulator (7812), but the 2v difference may be problematical (they work better with a 3v difference), or even a simple resistance/12v zenner/capacitor combo....

[GTom]

8 hours ago, Dr_Ju_ju said:

Personally, I'd drop the 14v down to 12v using either a regulator (7812), but the 2v difference may be problematical (they work better with a 3v difference), or even a simple resistance/12v zenner/capacitor combo....

Actually as far as I know, the HEQ5 loves 14V. The actual plan is to power everything with 4s LiFEPO4 banks without voltage conversion.

[michael8554]

You should already have inline fuses for your mount and other equipment.

If the peltier has a fault it shouldn't harm your mount if connected in parallel.

But an unfused short in the peltier circuit could lead to thermal runaway.

Michael

[malc-c]

The HEQ5 will run fine on 14v DC.   You could connect any other device to the same power supply provided there is no risk of reverse polarity.  You could use a suitably rated diode to give some protection against reverse polarity, but as the HEQ5 motor board has a power diode across the input, which offers some protection, but if that blows the board wont function (it's like they use the diode as a sacrificial fuse).  Naturally the higher the current draw the less time the batteries will last.