Hello everyone.
Some background - I have one of those chinese diesel heaters, which I'm using to heat a garage. Probably most of you are familiar with that units, but here is some basic info - the main heater body is enclosed with the motherboard+sensors unit inside a plastic case. The heater has a glow plug, that works only when the unit is starting (start the fire in the burner) and stopping (make sure to completely burn the fuel inside the burner) and two fans on a single motor. One fan is used to push fresh air in the burner, the other is used to push cold air in the case and thus transfer energy from the heater body. For PSU I use a PS3 power supply, which has 12v and 5v outputs. The heater works with 7-16V and it has no power regulation/stabilization for the glow plug and the fan (it has only for the ICs on the motherboard).
I guess many of you already see the problem, which will happen if the power supply is interrupted - the fan stops cooling the heater body while in the combustion chamber there are still fuel and (some) air to continue the burning process. This might cause temperature increase in the case, enough to damage the motherboard (the heater body can easily reach up to 210-220 C* when running).
So I'm thinking about some kind of a basic (and cheap) temporary/emergency power supply. What I have in mind is a car battery in parallel with the psu 12v rail and a 5V relay which will cut the pulse signal to the pump (see attached image). This way, when there is a mains interruption, the psu will die and the signal to the pump will be cut, which will be detected as an error by the heater's brain and will force it go into power off cycle. The normal power off procedure also keeps the fan running until the heater body reaches safe temperature.
When the glow plug is on, the unit consumes about 12-15 amps (~150watts if I remember correctly). When the glow plug is off (most of the time), the unit consumes less than 1 amp.
The psu specs are 12v 20+A and 5V 1A
So please check the drawing I made and give your suggestions on how to improve it. Thanks in advance.
Some background - I have one of those chinese diesel heaters, which I'm using to heat a garage. Probably most of you are familiar with that units, but here is some basic info - the main heater body is enclosed with the motherboard+sensors unit inside a plastic case. The heater has a glow plug, that works only when the unit is starting (start the fire in the burner) and stopping (make sure to completely burn the fuel inside the burner) and two fans on a single motor. One fan is used to push fresh air in the burner, the other is used to push cold air in the case and thus transfer energy from the heater body. For PSU I use a PS3 power supply, which has 12v and 5v outputs. The heater works with 7-16V and it has no power regulation/stabilization for the glow plug and the fan (it has only for the ICs on the motherboard).
I guess many of you already see the problem, which will happen if the power supply is interrupted - the fan stops cooling the heater body while in the combustion chamber there are still fuel and (some) air to continue the burning process. This might cause temperature increase in the case, enough to damage the motherboard (the heater body can easily reach up to 210-220 C* when running).
So I'm thinking about some kind of a basic (and cheap) temporary/emergency power supply. What I have in mind is a car battery in parallel with the psu 12v rail and a 5V relay which will cut the pulse signal to the pump (see attached image). This way, when there is a mains interruption, the psu will die and the signal to the pump will be cut, which will be detected as an error by the heater's brain and will force it go into power off cycle. The normal power off procedure also keeps the fan running until the heater body reaches safe temperature.
When the glow plug is on, the unit consumes about 12-15 amps (~150watts if I remember correctly). When the glow plug is off (most of the time), the unit consumes less than 1 amp.
The psu specs are 12v 20+A and 5V 1A
So please check the drawing I made and give your suggestions on how to improve it. Thanks in advance.
Attached Files
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