Drysuit heating controller options

[Richard Dayan]

I moved it to this thread. This is my heat controller. Im setting up a company that just sells these controllers for $300. Its 18 amps and fully variable many levels with a mechanical knob instead of on/off.

 

[Wibble]

I moved it to this thread. This is my heat controller. Im setting up a company that just sells these controllers for $300. Its 18 amps and fully variable many levels with a mechanical knob instead of on/off.

What are the specifications? Voltage in and out, current, control interface (i.e. how the button/knob works), depth.

Want something that will work from, say, 8V to 20V and delivers a constant 12V out. Needs to work with larger undersuits (BZ400 at 110W) plus heated gloves & socks, therefore up to 200W+ (e.g. ~18A at 12V)

This would save a small fortune in very expensive batteries.


Oh, and what about a nice container that takes a couple of DeWalt power tool batteries! Might be rather large though, given the size of a Blacktip DPV!

 

[broncobowsher]

8-20V input to get 12V output would take a buck boost convertor. And the amp draw when down to the 8V mark would be super ugly. And I can't think of a modern battery that would survive being run over that range of voltage (bank of batteries that is)
The best way is to keep the minimum pack voltage over the target voltage and run a buck circuit. Now make the buck circuit variable output to throttle the output below 12V (full power) and you just made a heat controller.

Get a more realistic battery pack parameters and the rest of the circuit gets easier. 8-20V input isn't a realistic battery range.

 

[Whitrzac]

Yeah. Using a 4s-5s pack and regulating down is easier. Its also less current drawn, and would have less of a voltage drop under load.

Realistically "tempurature" is subjective anyway. Having a constant output controller is a lot of extra work for not a lot of gain.

 

[Richard Dayan]

What are the specifications? Voltage in and out, current, control interface (i.e. how the button/knob works), depth.

Want something that will work from, say, 8V to 20V and delivers a constant 12V out. Needs to work with larger undersuits (BZ400 at 110W) plus heated gloves & socks, therefore up to 200W+ (e.g. ~18A at 12V)

This would save a small fortune in very expensive batteries.


Oh, and what about a nice container that takes a couple of DeWalt power tool batteries! Might be rather large though, given the size of a Blacktip DPV!

It's a 12-24 volt but works fine with 11.1v, it doesn't have constant 12v out. My solution to this problem of a weaker output from the battery at the end of the dive is to have an overpowered system and throttle back like in your car. For example, load up with everything bz400, gloves and socks ect run it at 75-80 or even 90 or even 92 percent then micro adjust the knob to compensate for voltage drop. Also having so many levels makes the heat output just perfect, maybe 100 is too much and 75% not enough then just adjust to 88 percent etc. The knob works like any knob on land just turn it for more power and turn it back for less, all positions on the knob actually do something like the volume knob on a speaker. It can also handle a full 18 amps at 24 volts for a 432-watt scooter.

 

[grantmac]

I think I'd rather have a step down converter so the power stays constant rather than having to throttle it up as it drains.

 

[Wibble]

The main challenge is that many (most?) divers already have the batteries which run at around 14.4 or supposedly 12 volts (which is actually 11V).

Having a DC to DC converter could give a constant output with a variable input.

One other small feature: you must be able to replace the E/O connector cables during the life of the converter -- they are almost guaranteed to break if folded, etc.

 

[Richard Dayan]

I think I'd rather have a step down converter so the power stays constant rather than having to throttle it up as it drains.

I am adjusting temperature anyways, if stationary I like it hot, if swimming I like it cold.

 

[bananafeller]

I moved it to this thread. This is my heat controller. Im setting up a company that just sells these controllers for $300. Its 18 amps and fully variable many levels with a mechanical knob instead of on/off.

How are the knob and container sealed? What depth rating are you expecting?

 

[Richard Dayan]

How are the knob and container sealed? What depth rating are you expecting?

I don't want to give away technical info on sealing, especially the knob. It's an art and I want to start a commercial company and don't want competitors to copy. I tested it at 150 ft. in real life and 6 atmospheres under test conditions. Right now there are only 5 external controllers for sale on the planet that I know of. Grail marine, Fathom Dive, UWLD, light monkey and Smartex.