How Power Magic Pro works

M8TJT

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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 12 or 12.5V

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.
 
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M8TJT

M8TJT

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Temp checks with BV in parking mode after 2 hours soak for each test using IR thermometer.
16Gb Blackvue card. BV body temp = 43C, ambient temp 28C
128Gb Samsung Evo Plus BV body temp = 41C, ambient temp 25C
 
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M8TJT

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Low Voltage Time delay
My assumption/findings at item 10 in post 1 was correct. I have done some more experimentation and found that if you connect a capacitor between the Red and Black wires and a diode in series with the red wire, you can generate a longish time delay.

The delay works like this:
1 With the PMP set to ON and ignition OFF (parking mode ON), it introduces a longish delay between the input voltage dropping below the PMP voltage setting and switching off the BV.
2. With the PMP switched OFF. It also introduces the same longish delay when you switch OFF the ignition. (This is a side effect of the main purpose above)

Right then. How to do it.
Connect an electrolytic capacitor (values below) between the red and black input wires. This can actually be done inside the PMP, and if you use a really small tantalum bead capacitor, it can be soldered to the bottom of the board where the cable plug is situated. Solder the capacitor between the second and third pins from the left when looking at the back of the pcb mounted plug, with the positive terminal of the capacitor to the red wire. Then cut the red wire at a convenient distance from the cable socket and insert a diode between the two cut ends, with the cathode end (the end with the band on it) connected to the PCB plug red and the anode connected to the red wire that goes to the ACC+. This can be insulated with tape, or better still, some heat shrink tubing.

Values:
The diode can be any small low current diode (I used a 1N 4004 because I had one to hand).
The capacitor value will depend on how long a delay you require.
4.7 microfarad = approximately 25 seconds delay
10 microfarad = approximately 50 seconds delay
47 microfarad = approximately 200 seconds delay (3 1/2 mins)

Larger values will fairly obviously give longer delays.
 
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Hillbilly

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Plain and simple Im not a tech but have played with these a bit
Conclusions
On the bench cameras require a 1amp power supply to fire up
Pmp in a car requires engine on for reliably operating. Found out by failing 4 then turned car on and all worked
Can work if red and yellow are combined on a perm power ( which defeats purpose of having it)

Will stutter on starting car if battery low.

Old ordinary PM was better as had lower cutoff and better time settings
 
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M8TJT

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You are absolutely correct on startup voltage. The thing will not switch an output on my power supply at 12V (yes it is accurate) I have to switch it to 13.5V before the PMP will switch on. I will try it on my variable PSU later and find out exactly what voltage does switch it.
 
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M8TJT

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On the bench cameras require a 1amp power supply to fire up
Yes to supply the demanded current of up to 400 odd mA, but more importantly, the voltage needs to be higher than the PMP set voltage by about 1/4V
 
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M8TJT

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Further to my post #3 re the diode in series with the red wire. I had not allowed for the fact that the diode itself has a 0.7V drop across it. The problem is that if the cutoff voltage is set to 12V (assume that it actually switches off at 12V) then due to the 0.7V drop across the diode, the PMP will switch off when the battery drops to 12.7V. This is not good.

I will try a germanium diode tomorrow (if I can find one in my bits box) as the forward voltage of one of those is only 0.2V rather than 0.7V so the cutoff voltage should then be 12.2V.

I have subsequently realised that it's the reducing voltage on the yellow wire that causes the low voltage trip to switch it off. So the above is a load of bull. Now to find out why mine really switches off when the car's Auto Start/Stop kicks in. That's when I can get the ASS to work. But that's another story.
 
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kbpark824

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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.
So, in laymen's terms, that ACTUAL cutoff voltage is 12.25V? Anything less than 12.25V and it shuts off, am I correct?
 
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M8TJT

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No. It switches off at 12V (or 12.5V) but does not switch on until the voltage is about 0.25V higher than the set voltage.
 
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M8TJT

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I used a 47 microfarad 16v tantalum bead capacitor. Gives just over three mins delay.
Still haven't fully investigated what led to my post #7.
It's that when my car's auto stop-start (ASS) stops the engine, the BV sometimes seems to time out more quickly that the delay voltage. The problem in investigating this 'feature, is the ASS rarely works, so it's a bit difficult to pin down. I will try it all again using a couple of PSUs to see what happens when I get the urge.
 

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I am thinking my PMP has been wrongly wired to be permanently live and it's only cutting out power to the dashcam because of the battery voltage drop according to the PMP setting ... how do I test this?

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)

1. If the PMP has been wired properly and is in OFF position, should 12V supply to BV start with ignition on ACCESSORY position or does it need the engine started?

2. So should the DashCam power off in about 5 seconds when the car engine is turned off when the PMP is in the OFF position? (mine takes several minutes at the moment)


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)

Can the PMP be cycled OFF and ON (as confirmed by light on the PMP and power to DashCam) by simply toggling the switch or does the engine needs to be powered on to effect the change in state from ON to OFF and vice versa


Thanks
 
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Hillbilly

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I have found that it really needs the engine to be started to fire it up Found out after installing a new one and it wouldnt work Took it back they tested 4 that also wouldnt work on a test battery. Came home reinstalled turned engine on and away it went as it needs MORE than the cutout voltage to fire it up

To answer your first and last question in the light of the above What would you think?????

Your second question solution is probably You have it connected to an ACC source that has a delayed shutoff time Like interior lights or similar
 
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M8TJT

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Please don't ask pretty much the same questions in different places. Answers will be all over the place.
Look for my answer in your other thread I think I have answered all your questions in one hit so I have no intention of repeating myself here.
And please don't shout.

...or does the engine needs to be powered on to effect the change in state from ON to OFF and vice versa
No, but the input voltage from the battery must be at least 1/4V above the cut off voltage set as I have said earlier in this thread which may involve starting the engine.
 

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Can the PMP be cycled OFF and ON (as confirmed by light on the PMP and power to DashCam) by simply toggling the switch or does the engine needs to be powered on to effect the change in state from ON to OFF and vice versa
Thanks
I have found with mine that I can toggle it off and on.. but only if the "PMP" has not turned itself off.. time and possibly voltage. If the PMP has turned itself off then I must start my vehicle to re-initialize / reset the unit.
 
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M8TJT

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Agreed. I'll modify my post above to include this. (I already had.)
 

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If the parking mode is on,
should the camera activates parking mode immediately after ignition is turned off And stays like this until ignition is turn on again?
Or like in my case parking mode is depending only on car movement and nothing to do with ignition.
Approximately 5 minutes even with engine running.
Thanks.


Sent from my iPad using Tapatalk
 
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M8TJT

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Your findings are absolutely correct.
The camera switching to its Parking Mode is only dependent on the car being stationary.
The camera switching to its Parking Mode is nothing to do with the PMP other than it keeps the voltage supplied to the cam with the ignition off.

Confusion can arise by folk referring to both the PMP being switched ON to provide output with ignition off and the cam switching into its 'no movement' Parking Mode as 'Parking Mode', as you have done above.:)

To summarise:
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)
 

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