PPO monitors

Packhorse · 29th January 2008, 06:42

Im looking at building a PPO display and HUD based around Opamps and not using micro processors as I have very little experiance with them.
I can quite easily build a HUD that turns on and off LEDs at setpoints but all others I have seen use micro processors. Is there anything wrong with opamp driven HUDs? To some extent they seem a little more reliable as there is less circuitry involved and no software.
Taking this one step further (in theory only) I could also add a second set of setpoints that could trigger a dil solinoid to flood the loop if the PPO gets too far out of range and no O2 or dil was added manually.

Thoughts?

DanFountain · 29th January 2008, 17:35

Thre have been a few threads her about this subject. In one from last April I posted a proposed schematic for an analog HUD - http://www.rebreatherworld.com/home-...2-meter-5.html.

There was also one about analog displays and appropriate considerations for opamps - http://www.rebreatherworld.com/home-...2-display.html.

Hope this helps.

-Dan

Packhorse · 30th January 2008, 02:11

Thanks Dan very helpfull.

Anyone got recommendations on a cheap, small, low current LCD panel meter with backlight (optional)?
Not to bothered if it needs an external opamp or not, but I think it may need to use a common ground????

paulraymaekers · 30th January 2008, 09:34

Quote: (Originally Posted by Packhorse)

Im looking at building a PPO display and HUD based around Opamps and not using micro processors as I have very little experiance with them.
I can quite easily build a HUD that turns on and off LEDs at setpoints but all others I have seen use micro processors. Is there anything wrong with opamp driven HUDs? To some extent they seem a little more reliable as there is less circuitry involved and no software.
Taking this one step further (in theory only) I could also add a second set of setpoints that could trigger a dil solinoid to flood the loop if the PPO gets too far out of range and no O2 or dil was added manually.

Thoughts?

why make it difficult when you can have it easy :-)

the problem will always be there, if you don't use a microprocessor, you have to open the box each time when you calibrate

paul

29th January 2008, 06:42	#1 (permalink)
Packhorse Custom Title Allowed! Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Jan 2008 Location: Auckland New Zealand Posts: 100	PPO monitors Im looking at building a PPO display and HUD based around Opamps and not using micro processors as I have very little experiance with them. I can quite easily build a HUD that turns on and off LEDs at setpoints but all others I have seen use micro processors. Is there anything wrong with opamp driven HUDs? To some extent they seem a little more reliable as there is less circuitry involved and no software. Taking this one step further (in theory only) I could also add a second set of setpoints that could trigger a dil solinoid to flood the loop if the PPO gets too far out of range and no O2 or dil was added manually. Thoughts? __________________ There are no stupid questions, but there are a LOT of inquisitive idiots.
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29th January 2008, 17:35	#2 (permalink)
DanFountain Custom Title Allowed! Current Rebreather/s: Home Build Other Rebreather/s: Home Build Join Date: Dec 2005 Location: Lake Superior Posts: 101	Re: PPO monitors Thre have been a few threads her about this subject. In one from last April I posted a proposed schematic for an analog HUD - http://www.rebreatherworld.com/home-...2-meter-5.html. There was also one about analog displays and appropriate considerations for opamps - http://www.rebreatherworld.com/home-...2-display.html. Hope this helps. -Dan __________________ Try not. Do - or do not. There is no try. -Yoda
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30th January 2008, 02:11	#3 (permalink)
Packhorse Custom Title Allowed! Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Jan 2008 Location: Auckland New Zealand Posts: 100	Re: PPO monitors Thanks Dan very helpfull. Anyone got recommendations on a cheap, small, low current LCD panel meter with backlight (optional)? Not to bothered if it needs an external opamp or not, but I think it may need to use a common ground???? __________________ There are no stupid questions, but there are a LOT of inquisitive idiots. Last edited by Packhorse : 30th January 2008 at 02:43.
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30th January 2008, 09:34	#4 (permalink)
paulraymaekers rEvo's daddy Current Rebreather/s: rEvo Other CCR Home Build Other Rebreather/s: rEvo Other CCR Home Build Join Date: May 2005 Location: belgium Posts: 1,439	Re: PPO monitors Quote: (Originally Posted by Packhorse) Im looking at building a PPO display and HUD based around Opamps and not using micro processors as I have very little experiance with them. I can quite easily build a HUD that turns on and off LEDs at setpoints but all others I have seen use micro processors. Is there anything wrong with opamp driven HUDs? To some extent they seem a little more reliable as there is less circuitry involved and no software. Taking this one step further (in theory only) I could also add a second set of setpoints that could trigger a dil solinoid to flood the loop if the PPO gets too far out of range and no O2 or dil was added manually. Thoughts? why make it difficult when you can have it easy :-) the problem will always be there, if you don't use a microprocessor, you have to open the box each time when you calibrate paul __________________ www.rEvo-rebreathers.com .... the earth is flat, Elvis is alive, and radial scrubbers give longer dwell time than axials...
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