Thread: How to Modify Respirator Helmet to Run off Direct DC

It should be feasable to do this, at the expense of having the unit attached to a cord whenever it is in use. Might not be a major issue for carving if you work at a bench while sitting, but would be a pain if you need even a moderate degree of mobility.

Issues to overcome.

1. You need an alternate power source capable of supplying about 2.7volts at about 1 amp continuously for your required run duration.

2. You need to provide a flexible cable and connector system to get power into the motor/filter system reliably. This needs to penetrate the filter unit housing in an airtight manner to avoid efficiency loss, and also needs adequate strain relief to avoid damaging the airtight seal over time.

3. You need to consider whether you want to retain the original battery operated functionality for away from the bench jobs, or if you can effectively use the unit at all times in an umbilical mode dependant on external power.

To have umbilical and internal power, you must install a switch so that the batteries are isolated from the external power supply, or the external supply will attempt to charge the batteries when connected, potentially leading to overcharging and the batteries venting. There is absolutely no way that you want to risk this occuring as the vapour from the venting cells will be directed straight to the headsheild and your lungs. If you go this route, the switch and mounting must also be airtight to prevent leakage.

Alternatively, if you see no future need to have self contained operation, the batteries may be removed permanently and recycled.

If I was to undertake this project, I would use balanced microphone cable possibly of the 'curly cord' variety and XLR style connectors, for the umbilical connections. Use a pigtail about 6 to 8 inches long hanging out of the filter/motor unit terminating in an inline 3 pin XLR male connector. The pigtail can be sealed at the penetration into the filter/motor unit with silicone or similar sealant.

Then fit a matching female XLR connector to the end of the umbilical. I have suggested a 'curly cord' style umbilical as it will allow some movement without leaving cable hanging or looping on the floor as a hazard. Do not use telephone or electrical guitar curly cord as the conductors will not carry the required current reliably for long. Balanced microphone curly cords are not common but are available and have two conductors and a sheilding wire sheath. A guitar cable has one conductor and the shielding sheath. Do not attempt to feed power through the sheilding sheath.

I think the quickest and easiest way is to get a 2nd battery pack, and have it on charge ready to go when the first one cuts out. That's what the builders do for their battery operated nail guns etc

eBay is a great place to get these types of batteries, often a fraction of the price of the original brand name batteries

Hi there,

Just thinking about this project myself

Looking at the Triton website - noticed that the Power Module is 6 volt DC.

Would anything less than 6 volts provide the necessary airflow?

Would the exisitng transformer provide enough power to keep the unit operating at the required rate .... (I have my doubts about this - but it would be a simple solution)?

Like the idea of the curlie cords.

I do most of my work in the one place due to space limitations. So being tethered to a power supply won't be a major problem for me.

Interwood

The existing power supply may be underpowered for actual operation - more likely sized for overnight charging while the batteries last for four hours...that would indicate that you might need a bit more ooomph to run the motor. Try this:

6 volts DC regulated switchmode power supply - $22.

Switchmode Mains Adaptor 6VDC 2.2A - Jaycar Electronics

I'd take the batteries out to avoid overcharging, and simply wire up an adaptor that connects to the existing leads from the battery compartment, or even do a horrible 'wrap copper wire around the terminals meant for the battery and mummify in insulation tape' job if you aren't confident with a soldering iron.

This is a simple modification to do. I have done this for some of my work test equipment (after seeing the price to repack the battery).
The way I would do it is cut the battery pack away making sure to leave a couple of inches of cord on the battery end. Then solder on an female audio jack on to the battery pack and and the same on to the power supply. Then solder a male audio jack onto cord going to the respirator. This way you can switch between the power pack and the battery pack in seconds.
Use a 6.5mm mono plug of good quality i.e. metal.

Hope that makes sense.

The picture is of a stereo jack and the wrong size but you get the idea.

Thanks for all the quick responses. I guess it might be a pain to use the cord since I do move around a bit. hmm... Maybe it would be possible to just buy another set of batteries of the right voltage and other specifications and wire them in, without buying the entire Triton battery pack?

Hi Didgemaker,
You have me puzzled as to why you use a Res. for Carving. I do a bit of Carving & have never needed a Resp.
Many years ago a Chap in our Club, devised a way of using a Powerpack, that plugged into the electricity, & came out at the Voltage needed to run his Air Helmet. So he used a pull apart plug system, as when he wanted to move to another part of his Shed, he just disconnected himself at the Plug. The Plug he used came from a Fluorescent Light, where you put it together in the back.
I might add, he used a long length of Lead, so as he could move around a fair bit.
Worked for him. Hope this may help
Regards,
issatree.

Have read through the posts following mine and see people talking about 6V supplies.

While I have not had anything to do with these units personally, I did take the time to ready an online version of the manual and some online reviews before making my original response, and I am a qualified electronic engineer so I have a basic idea of what happens.

The unit is powered by two 4AH nicad batteries built into the filter unit and not readily swapable as with cordles tools. This works against the suggestion of getting another battery pack and swapping when the first becomes incapabable of running the unit. It appears that you have to have a complete filter/fan unit to do this convieniently.

The battery pack installed has a working range of approximately 2.8V when fully charged to about 2.2V when fully discharged, so attempting to operate at 6V would significatly shorten the life of the motor in the unit.

I have subsequently thought of an alternative source of a suitable 'curly cord', being those mains ones used for for shavers etc, with the connectors replaced with non mains ones to prevent any possibility of direct mains connection.

I recommended XLR style connectors because they lock together and have higher reliability than headphone and guitar connectors and better solder cups to accomodate medium sized cables to carry the current required.

Why not just plug the charger in.
I used hang a 240v lead off the ceiling and plug the charger in.
Provided you stay withing the range of the wiring all, all works fine.

Originally Posted by malb

The unit is powered by two 4AH nicad batteries built into the filter unit

Actually 5 batteries, 3 in the base compartment and 2 near the fan.

Hi All,

5 x 1.2 volts = 6 volts

Motor is not able to be removed or viewed without wrecking impeller, which I don't want to do. I can see the letters ...NSON .... 361 on the side of the motor case. Googling the web, found a Johnson 6v DC electric motor. Will continue looking to try to find out current draw.

5 x 1.2 volts = 6 volts

Not necessarily correct. Depends on the battery connection setup. If they are all in series, head to tail, +ve to -ve, then you get 6 volts.

If they are in parallel, +ve to +ve, then the resulting voltage is only 1.2V.

From the photo, looks like the batteries are a combination of series and parallel, so 2.8V sounds viable

The batteries ARE wired in series (they have white cardboard on the positive ends together with a black cross to indicate positive end / black negative sign for the other end! - and yes you can see these in the second photo) but the give away has to be the label on the unit.

So yes ... necessarily correct!! 6.0 vDC

Confirmed by actually looking at the batteries, wiring of batteries, specification sheet from Triton website and the label on unit.

Also noted by other forum members Sprog and Ilya.

The charger for the powered respirator has been discussed by The Old Bloke.

Originally Posted by didgemaker

Hello all. I have the Triton Powered Respirator helmet and wanted to know how I can modify it to run off direct DC with some kind of adapter.
Would someone be so kind as to provide some detailed instructions on how to go about this?
Thanks in advance for your replies.

Check out the Sydney Woodturners Guilds November 2009 newsletter. There is an excellent article on modifying the Triton respirator to use a second battery pack with full instructions and circuit diagram.

Sydney Woodturners Guild Triton Mod