Idea for glow plug controller/Wilson switch alternative

[RufusTheDufus]

I decided to work on a prototype/proof of concept with an Arduino. For the moment I'm just testing with manual switches to test PWM support for 10.5, 8.5v adn 6v glow plugs.

The idea is to have a pin-compatible replacement glow plug relay that will work in any 12 volt 4 or 6 cylinder Cruiser. It will emulate the Superglow system in software using PWM for non-Superglow applications. Should be able to keep the in-dash manual-glow system's 'glow controller' or ditch it, won't matter. If the stock Superglow system messes up rip it out and replace it with this gadget.


I'm considering doing a non-pin-compatible version that will provide diagnostic feedback for failed plugs. The idea would be to report glow plug failures morse code style through a dash mounted blinking light.

 

[BreckenridgeCruiser]

Rufus,

I'd be interested in this project of yours. Even if it is something simply to allow me to glow after the truck is been started and not burn out my plugs by hitting it with the extra voltage coming from the alternator, that would be worth it. Keep us updated on the progress!

 

[RufusTheDufus]

At some point I'll be looking to send out a few freebie prototypes for testing and feedback.

 

[BreckenridgeCruiser]

Count me in! It'd be for a 1HZ and I want to integrate it into some of the switching from the superglow I removed. Give me a shout if you want to chat about it more!

 

[Biche]

I decided to work on a prototype/proof of concept with an Arduino. For the moment I'm just testing with manual switches to test PWM support for 10.5, 8.5v adn 6v glow plugs.

The idea is to have a pin-compatible replacement glow plug relay that will work in any 12 volt 4 or 6 cylinder Cruiser. It will emulate the Superglow system in software using PWM for non-Superglow applications. Should be able to keep the in-dash manual-glow system's 'glow controller' or ditch it, won't matter. If the stock Superglow system messes up rip it out and replace it with this gadget.


I'm considering doing a non-pin-compatible version that will provide diagnostic feedback for failed plugs. The idea would be to report glow plug failures morse code style through a dash mounted blinking light.

This is a cool prototype. Would you keep the arduino board or switch to a custom one? If you do a 24V version I would be interested for sure.

 

[RufusTheDufus]

I'd switch to a full custom board. The Arduino is just for getting a quick working code base and to figure out heat sink requirements. Some of these components can generate a TON of heat.

I should be able to make it work in either 12v or 24v applications. The only concern I have is that I don't have a 24v vehicle to do any testing on. The MOSFETs I'm using are rated for 28v continuous use so they should work. I'd just need to design the power supply to handle it and throw in some protection mechanisms to be sure the MOSFETs are never enabled if the supply voltage is >=28v. It wouldn't be an issue for the pre-start glow period, but the 28v limit could be an issue for after glow when the alternator is spinning.

 

[RufusTheDufus]

A little more progress. Installed an LCD display on the Adruino for testing purposes. The pre-glow and after-glow code is worked out and visible in this video. (BTW, I'm using 8.5v plugs in the video.)

I'm going to use two trim pots to set the pre-glow and after-glow duration. I'm thinking the pre-glow period pot should support a range of 1 to 60 seconds and the after-glow should be adjustable for 15 to 360 seconds. Are those reasonable time periods?

 

[Diesel42]

That's amazing. Keep up the great work. This is a great help to the LC community.

 

[Biche]

I'm currently using a manual switch for my glow plugs, 60 seconds pre-heat sound a little bit excessive in my opinion.

Having an arduino in the truck and a LCD, you could hook up some sensors (like voltage) and get a nice on board computer.

 

[RufusTheDufus]

The motivation of a 1 to 60 second preglow range is based on supporting the existing stock wiring. If someone has the older manual 'glow controller' system (i.e. the big hot resistor in the dash) they may need a longer glow period than someone that chooses to wire this thing directly to their glow plugs. My manual glow 82BJ42 will take 45 seconds when it's -26degC like it was yesterday when I woke up.

If there's never a need for a max of sixty seconds I can certainly adjust it down to 45. I do plan to support reading the water temp sensor as a way to modify the pre-glow period. So if the max is 60 seconds when it's -26C, then it might only do 45 seconds at -10c. I haven't worked out that part of the functionality yet.

The Arduino and the LCD are only prototyping tools. They won't be part of the final circuit.

 

[RufusTheDufus]

Last night I ran a little bit of a torture test on the prototype for three hours. I set up some test code that loops the controller through a 30 second pre-glow + a 120 second afterglow + a 10 second pause. That ran for 3 hours straight last night. I'm logging input voltages and heat sink temps. The glow controller should never need to operate in these conditions but I want to be sure it doesn't cause the MOSFETs to fail or overheat in the event there's a wiring fault. (The final version of the board will have a thermistor that monitors the ambient air temp inside the enclosure as an additional safety measure.)

I'm running the same code today with a 45 second pre-glow and 60 second afterglow.

 

[cody c]

Last night I ran a little bit of a torture test on the prototype for three hours. I set up some test code that loops the controller through a 30 second pre-glow + a 120 second afterglow + a 10 second pause. That ran for 3 hours straight last night. I'm logging input voltages and heat sink temps. The glow controller should never need to operate in these conditions but I want to be sure it doesn't cause the MOSFETs to fail or overheat in the event there's a wiring fault. (The final version of the board will have a thermistor that monitors the ambient air temp inside the enclosure as an additional safety measure.)

I'm running the same code today with a 45 second pre-glow and 60 second afterglow.

I'm interested, I'd like to get a remote starter in my hilux, and having some sort of glow system would be required to get it to start remotely in cold weather.

I still have the original system, but it failed at some point and was replaced by the wilson switch

 

[RufusTheDufus]

I stumbled onto something interesting this evening while working on the input voltage compensation code. I've got some logic that monitors the battery input voltage and adjusts the output duty cycle to match the glow plug voltage in both pre-glow and afterglow periods.

On a 12v glow system 6v plugs directly wired to the relay are the way to go. With 6v plugs I can get full glow out of a run down battery (under load) all the way down to 7.5v. Doubtful that a 7.5v battery will crank the engine over but at least the glow plugs will get nice and hot.

 

[bj40green]

......to match the glow plug voltage in both pre-glow and afterglow periods.

The matching at pre glow I understand but I wonder what good it is to match the voltage on afterglow because when the engine is running the voltage is 13.2V or so at idle, More when you rev up a bit. But, I must say..... it's a nice feature.

Rudi

 

[RufusTheDufus]

...I wonder what good it is to match the voltage on afterglow because when the engine is running the voltage is 13.2V or so at idle,

IMO, the afterglow compensation is actually more important than pre-glow. Too much voltage could burn out the plugs prematurely.

I have this problem with my manual/momentary switch and the stock relay. (The optional owner-installed switch in red on the diagram below.) I will manually 'pulse' the plugs on/off at 1 second intervals to act as an afterglow. If I set the hand throttle to raise the idle when warming up the engine the alternator can raise the voltage beyond the plug's rating.

Borrowing an image from lostmarbles:

 

[FatalErrorStu]

IMO, the afterglow compensation is actually more important than pre-glow. Too much voltage could burn out the plugs prematurely.

I have this problem with my manual/momentary switch and the stock relay. (The optional owner-installed switch in red on the diagram below.) I will manually 'pulse' the plugs on/off at 1 second intervals to act as an afterglow. If I set the hand throttle to raise the idle when warming up the engine the alternator can raise the voltage beyond the plug's rating.

Borrowing an image from lostmarbles:

Hi Rufus,

what was the outcome of your project, did you succeed in getting this working?

Kind regards.

 

[RufusTheDufus]

Never got beyond the breadboard prototype stage. I was hoping to design something that would plug in to the stock wiring harness and bolt to the firewall at the stock locations. The problem I ran into was the size of the heat sink(s) required to dissipate the heat of the mosfets. They would simply be too large, and kind of expensive too. I didn't think I could package it in a way that would fit in the stock location and be well within safe operating temps. Seems there's a reason most glow controller systems are in the engine compartment and not under the dash.

 

[FatalErrorStu]

Never got beyond the breadboard prototype stage. I was hoping to design something that would plug in to the stock wiring harness and bolt to the firewall at the stock locations. The problem I ran into was the size of the heat sink(s) required to dissipate the heat of the mosfets. They would simply be too large, and kind of expensive too. I didn't think I could package it in a way that would fit in the stock location and be well within safe operating temps. Seems there's a reason most glow controller systems are in the engine compartment and not under the dash.

OK, thats a shame. I am currently chasing a solution to my messed up glow setup in another forum post and I came across this one from you and your solution sounded interesting. You are probably quite good with electrics I suppose? This is my post if you are interested: Partial Wilson switch/total glow mess 24v BJ40 with 3B - https://forum.ih8mud.com/threads/partial-wilson-switch-total-glow-mess-24v-bj40-with-3b.1244327/

I also had an Arduino idea for a nice timer connected to the glow button using a small oled display and counts how long you hold the glow button to give you some feedback. I am not very good with electrics but I can code.

Stuart.

 

[RufusTheDufus]

You could updated that Arduino code to cycle a mechanical relay every 1 second for an after glow. Maybe slightly less than a 1 second interval would be OK as well. Too fast and you'll kill the relay contacts.

20+ years ago I was a computer engineer. It's fun to tinker on little projects sometimes but I don't have much time these days. I'll jump in on your other topic.

 

[FatalErrorStu]

You could updated that Arduino code to cycle a mechanical relay every 1 second for an after glow. Maybe slightly less than a 1 second interval would be OK as well. Too fast and you'll kill the relay contacts.

20+ years ago I was a computer engineer. It's fun to tinker on little projects sometimes but I don't have much time these days. I'll jump in on your other topic.

Thanks for replying on my other thread. So its not an issue to connect an Arduino or something similar to 24v with a DC to DC converter or something like that? I would like to add some modern touches to my Land Cruiser without making things too complicated or over the top.

Thanks for your advice again.