What is Glow Plug Driver?
This device may be known as Remote Glow Plug or Auto Glow Igniter. Thank to this innovation it saves my time as well as my hand during engine starts up. I still remember the accident that was once happened to my hand when trying to unplug the glow plug igniter by accessing it over the propeller. That recklessness caused me a bad cut and resulted in 14 stitches on my hand and left me a scar until today.
The glow plug driver is a brilliant gadget that seems to be indispensable now for it is not only assisting me during the start up but also providing the engine boost up during the flight. You may realize that when the engine is set for idle during some maneuver a sudden pick up of the speed might cause rich mixture and the glow plug might fail to maintain the heat. This can happen in both two and four stroke engine and according to this the engine may suffocate and lead to smother in an extreme situation.
The engine with integrated pump is not a solution causes it does not help maintain the heat in this situation. When the mixture is too rich we need more heat to burn out surplus fuel in the cylinder otherwise the engine may stop running. The glow plug driver is also provided with the boost up feature that helps warm up the glow plug for the entire flight.
The current supplies during the boost up period is minimal, not as much as it is during the engine start up, thus saving the battery so that it can boost up the engine and maintain enough heat for good ignition. This device also has variable current boost up in relation to the temperature (or resistance) of the glow plug. In case of engine overheating the glow plug driver will stop supplying the current to keep the engine cool down and running normally.
The circuit can be illustrated as shown here.
The best use of this device, according to my trial and experience, is to apply at least 5A.BEC to supply the receiver and the glow plug driver. I always use three cells Li-Po 2200mAH battery with this BEC and select the required voltage to be 4.8V. The advantage is I can fly and boost my plane for numerous flights without recharging the battery – sounds good isn’t it?
You need to have a transmitter with a selected three- step switch and, preferably, the radio channel could be assigned to any switch you choose. The operation will be OFF – ON1 –ON2 which can refer to as Operating, Boosting, and Starting. Once your model plane is ready to start the selector switch which corresponds to the glow plug driver must be switched to ON2 position where the glow plug is fully heated for 30 seconds.
At this moment the engine is waiting for a starting process therefore you can apply your engine starter. After such period is ended the glow plug driver will switch to a boost mode where appropriate current is emitted to boost up the glow plug at near red heat point for 5 minutes. Since the engine is already running and the glow is fully activated so this boost up current just merely maintains the heat so as to stabilize combustion which is superb in an idle running.
What happen in a real use of this device?
This is clearly convinced by me as my engine revolution can be lowered without smothering. This indicates that during the idle run up the heat is not enough for the glow plug and when a sudden rich mixture is flowing in the engine due to a quick acceleration it might cause the engine to quit. For this reason the boost can be primarily used during landing but boosting the engine for the entire flight is even safer.
If you are worried that the boosting might fail the electrical system in case the battery is weakening. Just relax since the glow plug driver has automatically cut out off function when the battery voltage is dropping near 4.8 volt. So it is fully convinced that your servo and receiver still have enough power to function well for the whole flight. Since this might be the case it makes me intend to use Li-Po battery with BEC to supply the electrical system. This ample power will last for a whole day flight. Am I fully relied on this configuration? Of course I am since all of my nitro planes are equipped with this gadget and I have confidence that the electrical system is stable and blessed with good supply for a whole day. The only draw back is you need to spend more money for the BEC and Li-Po battery. Better or not you decide.
Good or bad device indeed?
No bad Con for me and it rather makes me addict to it. Same for my friends in the flying club they seem to use it more on a four stroke engine. As the engine was upside down on a scale plane it is more difficult for the glow plug igniter to access the glow plug. Glow plug driver helps you out of this boring task and at no matter of time you will forget the conventional glow plug igniter. This device is fun to play on and it makes more sense to use it as an engine booster for the whole flight. However, according to my experience, the BEC and the Li-Po battery work well as a power supply for the electrical system.
I am quite amazing that so many RC folk do not really know what the glow plug driver is all about. They thought that it was merely a remote starter device (auto glow) but when I shown them all the features it had they seemed to be impressed. That is why this product was not fully convinced the first time it was launched. Many RC flyers are skeptic of its reliability and its power consumption for fear that it might exhaust the power supply. Well time has proved that this innovation will last for next decades.
So I personally have positive view on this glow plug driver, the only thing I need to wait and see is how long it will last. Concerning the safety reason I am not much worry about this since it is plugged in its dedicated channel so it works separately from the other electrical devices. In case this device fails it will just stop boosting but the other electrical devices will be working as usual.