erkme73
Well-Known Member
- Joined
- Jun 30, 2013
- Messages
- 673
- Reaction score
- 367
- Country
- United States
- Dash Cam
- a119v3 x 4
I'm not an electrician or engineer. But, I've always felt having a dash camera shut down as I leave my vehicle made little sense. Maybe it's paranoia, but I figure if someone was mad about my driving habits, and they're motivated enough to damage my vehicle, it'll likely be shortly after I park and walk away.
The problem with wiring these cameras to constant 12V is that, over time, they will kill the vehicle's starting battery. Devices designed to kill power to a circuit when the vehicle battery drops to a certain level are intriguing, but ultimately, I think they too stress the batteries by running them down more than normal.
I've found a very nice "Swiss Army knife" of timed relays on Amazon for about USD17. It can be configured about 18 different program scenarios. The one I (we) need for our dash camera is one that stays on for X:XX after the accessory power has turned off.
It comes just like it looks, so you'll need to pick up a small project box (2" x 3") from Radio Shack.
By supplying the relay with constant 12V, and using the ACC power to 'trigger' the relay timer, any circuit can be powered for a user-defined amount of time after the ACC power has dropped.
Of course, the problem with most dash cameras is that they require 5VDC, not 12. Since the relay contacts are isolated, you can switch 5VDC. But, the problem with such a low voltage is that if you're powering something at a distance of more than a couple of feet, or powering more than one camera, the 5VDC at the camera may drop below whatever minimum the camera needs.
For that reason, I'm switching 12VDC, and running that to the locations where my cameras are installed. Since I'm powering four cameras (one facing each direction, just above the camera location (above the headliner), I've terminated the 12VDC run with a small voltage regulator that drops the voltage to 5VDC. To the output side of the regulator, I solder a micro USB cable.
This regulator is about 3/4" wide, and about 1.5" long. It fits inside heatshrink tubing and disappears behind the headliner trim. The potentiometer on the regulator lets you dial in your exact output voltage, regardless of input voltage (up to 35VDC).
The end result is that the cameras stay on, in my case, for 1 hour after I leave the vehicle. In most cases, what ever errand I'm running, I'm back to the car before the hour expires. And even if not, chances are, any one bent on doing harm to my vehicle will most likely do it within the first hour.
The problem with wiring these cameras to constant 12V is that, over time, they will kill the vehicle's starting battery. Devices designed to kill power to a circuit when the vehicle battery drops to a certain level are intriguing, but ultimately, I think they too stress the batteries by running them down more than normal.
I've found a very nice "Swiss Army knife" of timed relays on Amazon for about USD17. It can be configured about 18 different program scenarios. The one I (we) need for our dash camera is one that stays on for X:XX after the accessory power has turned off.
It comes just like it looks, so you'll need to pick up a small project box (2" x 3") from Radio Shack.
By supplying the relay with constant 12V, and using the ACC power to 'trigger' the relay timer, any circuit can be powered for a user-defined amount of time after the ACC power has dropped.
Of course, the problem with most dash cameras is that they require 5VDC, not 12. Since the relay contacts are isolated, you can switch 5VDC. But, the problem with such a low voltage is that if you're powering something at a distance of more than a couple of feet, or powering more than one camera, the 5VDC at the camera may drop below whatever minimum the camera needs.
For that reason, I'm switching 12VDC, and running that to the locations where my cameras are installed. Since I'm powering four cameras (one facing each direction, just above the camera location (above the headliner), I've terminated the 12VDC run with a small voltage regulator that drops the voltage to 5VDC. To the output side of the regulator, I solder a micro USB cable.
This regulator is about 3/4" wide, and about 1.5" long. It fits inside heatshrink tubing and disappears behind the headliner trim. The potentiometer on the regulator lets you dial in your exact output voltage, regardless of input voltage (up to 35VDC).
The end result is that the cameras stay on, in my case, for 1 hour after I leave the vehicle. In most cases, what ever errand I'm running, I'm back to the car before the hour expires. And even if not, chances are, any one bent on doing harm to my vehicle will most likely do it within the first hour.
