M8TJT
Well-Known Member
- Joined
- Feb 14, 2018
- Messages
- 1,376
- Reaction score
- 721
- Location
- East Sussex
- Country
- United Kingdom
- Dash Cam
- 2x750 2CH
PMP= Power Magic Pro
BV = Blackvue Camera
Before I start, this is a summary of what the PMP is designed to do.
What it does
With the PMP switched OFF, the cam will switch off after a short delay, thus during normal use it will never enter its Parking Mode.
If the PMP is switched ON, providing the battery has not dropped below your set threshold and timer has not timed out, the cam will remain on indefinitely and switch into Parking Mode after a few mins of non-movement. It switches out of its Parking Mode when it detects the car has moved from its parked location (normally a couple of tens of yards)
How it does it
I have a spare PMP and am having a 'play' on the bench. Due to note 3 below, my bench power supply is switched to a 13.5V output.
Notes:
1. Unless the Yellow wire is connected to a 12V supply, the PMP will not output 12V even if the Red wire is connected to a 12V supply.
2. If you just connect the Yellow wire to 12V with the PMP switched ON, the PMP will not output 12V unless you either switch it OFF then ON or put 12V on the Red wire (switch ON the ignition)
The Red wire is a high impedance trigger. It will trigger the PMP just by holding the wire and then touching the 12V supply
3. If the 12V supply is at or lower than the voltage set on the PMP (12 or 12.5), the PMP will not output 12V to the BV, giving the impression that it is faulty. On my test rig, if I switch the PMP voltage selector to 12V and apply 12V to the PMP, it will not switch on the BV, but if I increase the voltage to 13.5V, it fires up as expected.
You will likely need to START THE CAR to get the battery over the 12 or 12.5V threshold.
4. With Yellow wire connected to permanent 12V and the PMP switched OFF:
When you connect the Red wire (ACC+) to 12V (switch the ignition ON), the 12V is immediately switched to the BV and it starts
When you remove the Red wire from the 12V supply (Switch the ignition OFF), the 12V is removed from the BV after a 5 second delay.
(Normal operation with PMP switched OFF)
5. With Yellow connected to permanent 12V and the Red not connected (Ignition switched OFF) :
When you switch ON the PMP, 12V is switched to the BV and remains at 12V (I assume until the timer runs out after 12 hours or whatever)
When you switch OFF the PMP, the 12v is removed from the BV immediately.
(This would be normal operation with the car ignition switched OFF)
6. With Yellow connected to permanent 12V and the Red connected to 12V (Ignition switched ON) :
The switch position on the PMP is irrelevant. as soon as you switch on the ignition, 12V is switched to the BV and remains at 12V (I assume until the timer runs out after 12 hours or whatever)
When you switch OFF the ignition, the 12v is removed from the BV after a 5 second delay.
(This would be normal operation with the car ignition is switched ON/OFF)
7. After reducing the input voltage to the PMP to 9V, there is a 5 second delay before the PMP switches OFF the voltage to the BV. But once it has switched it off and then the voltage is restored, you need to either power cycle the PMP or switch the ignition ON to get the BV to fire up. But if the voltage is restored to 13.5V before the 5 second timer has timed out, the BV remains powered. Restoring the voltage to 12V (with the PMP voltage set to 12V) does not work, the re-applied voltage needs to be higher than the PMP 'cut off' voltage. (START THE CAR if the PMP does not switch on) With PMP 'cut off' set to 12.5V and the input to 13.5V, reducing the supply to 12V starts the cut off timer that switches off the cam after 5 seconds, but restoring the voltage to 13.5V within the 5 second delay keeps the BV running.
8. At a supply voltage of 13.5V, my BV 550 takes about 250mA and about 420mA with the rear cam connected. It makes little difference when in Parking mode to the current consumption.
My 750 2CH draws about 200mA in normal recording with no rear cam attached at 14V.
9. The only way I can get the PMP to stay powered when it is not supposed to be, it by connecting the Red wire to a permanent live as well as the Yellow wire.
10. As the red wire is a high impedance input to the PMP, this looks like a possible route to extending the switch off delay with a simple external diode/C/R circuit.
I'm going to do some temp checks with different SD cards in it later
EDIT 08/08/18 16:45
Addendum to item 3. The PMP when set to 12V needs a supply of at least 12.25V to switch on and if set to 12.5V it requires at least 12.75V to switch on.
Item 8 edited to latest info.
EDIT 05/03/19
Added What it does at the start of the post
EDIT 24/06/19
Edited to highlight the importance of starting the car engine. As this seems to be a common 'mistake' leading to the "My PMP doesn't work/switch on" problem.
BV = Blackvue Camera
Before I start, this is a summary of what the PMP is designed to do.
What it does
With the PMP switched OFF, the cam will switch off after a short delay, thus during normal use it will never enter its Parking Mode.
If the PMP is switched ON, providing the battery has not dropped below your set threshold and timer has not timed out, the cam will remain on indefinitely and switch into Parking Mode after a few mins of non-movement. It switches out of its Parking Mode when it detects the car has moved from its parked location (normally a couple of tens of yards)
How it does it
I have a spare PMP and am having a 'play' on the bench. Due to note 3 below, my bench power supply is switched to a 13.5V output.
Notes:
1. Unless the Yellow wire is connected to a 12V supply, the PMP will not output 12V even if the Red wire is connected to a 12V supply.
2. If you just connect the Yellow wire to 12V with the PMP switched ON, the PMP will not output 12V unless you either switch it OFF then ON or put 12V on the Red wire (switch ON the ignition)
The Red wire is a high impedance trigger. It will trigger the PMP just by holding the wire and then touching the 12V supply
3. If the 12V supply is at or lower than the voltage set on the PMP (12 or 12.5), the PMP will not output 12V to the BV, giving the impression that it is faulty. On my test rig, if I switch the PMP voltage selector to 12V and apply 12V to the PMP, it will not switch on the BV, but if I increase the voltage to 13.5V, it fires up as expected.
You will likely need to START THE CAR to get the battery over the 12 or 12.5V threshold.
4. With Yellow wire connected to permanent 12V and the PMP switched OFF:
When you connect the Red wire (ACC+) to 12V (switch the ignition ON), the 12V is immediately switched to the BV and it starts
When you remove the Red wire from the 12V supply (Switch the ignition OFF), the 12V is removed from the BV after a 5 second delay.
(Normal operation with PMP switched OFF)
5. With Yellow connected to permanent 12V and the Red not connected (Ignition switched OFF) :
When you switch ON the PMP, 12V is switched to the BV and remains at 12V (I assume until the timer runs out after 12 hours or whatever)
When you switch OFF the PMP, the 12v is removed from the BV immediately.
(This would be normal operation with the car ignition switched OFF)
6. With Yellow connected to permanent 12V and the Red connected to 12V (Ignition switched ON) :
The switch position on the PMP is irrelevant. as soon as you switch on the ignition, 12V is switched to the BV and remains at 12V (I assume until the timer runs out after 12 hours or whatever)
When you switch OFF the ignition, the 12v is removed from the BV after a 5 second delay.
(This would be normal operation with the car ignition is switched ON/OFF)
7. After reducing the input voltage to the PMP to 9V, there is a 5 second delay before the PMP switches OFF the voltage to the BV. But once it has switched it off and then the voltage is restored, you need to either power cycle the PMP or switch the ignition ON to get the BV to fire up. But if the voltage is restored to 13.5V before the 5 second timer has timed out, the BV remains powered. Restoring the voltage to 12V (with the PMP voltage set to 12V) does not work, the re-applied voltage needs to be higher than the PMP 'cut off' voltage. (START THE CAR if the PMP does not switch on) With PMP 'cut off' set to 12.5V and the input to 13.5V, reducing the supply to 12V starts the cut off timer that switches off the cam after 5 seconds, but restoring the voltage to 13.5V within the 5 second delay keeps the BV running.
8. At a supply voltage of 13.5V, my BV 550 takes about 250mA and about 420mA with the rear cam connected. It makes little difference when in Parking mode to the current consumption.
My 750 2CH draws about 200mA in normal recording with no rear cam attached at 14V.
9. The only way I can get the PMP to stay powered when it is not supposed to be, it by connecting the Red wire to a permanent live as well as the Yellow wire.
10. As the red wire is a high impedance input to the PMP, this looks like a possible route to extending the switch off delay with a simple external diode/C/R circuit.
I'm going to do some temp checks with different SD cards in it later
EDIT 08/08/18 16:45
Addendum to item 3. The PMP when set to 12V needs a supply of at least 12.25V to switch on and if set to 12.5V it requires at least 12.75V to switch on.
Item 8 edited to latest info.
EDIT 05/03/19
Added What it does at the start of the post
EDIT 24/06/19
Edited to highlight the importance of starting the car engine. As this seems to be a common 'mistake' leading to the "My PMP doesn't work/switch on" problem.
Last edited: