Stabilizer bars and towing mirrors
- Thread starter Paul Costa
- Start date
I installed a wired camera on the van and wired it using some spare pins on the 12 pin connector and then back to a selector switch in the car.
The switch allows me to select the camera on the back of the car or the caravan. I also doubled up the input from the van into the aux connection so I can have the van camera on all the time if I want to, and it automatically comes on when reverse is selected.
This setup works really well for hitching up and towing whilst only having the single screen.
Her is the circuit that I put together that allows the car or caravan connector to be used for reverse and detecting the presences of the caravan and using the correct camera and also being able to select either camera. I have not used it and may not as I have changed GPS and may be able to use multiple inputs and the reversing wire on the GPS.
This design was more for a single input GPS that detected a video feed on the video input and would switch it in.
There are two options, the second one uses a double pole triple throw (DPTT) switch. The problem with this was that I could not readily find a switch that looked the part and was actually DPTT. They are all On/Off/On which is different.
So a quick how it works (using the first option with two relays:
Switch in Off position gives you automatic reverse, GPS detects video feed and displays.
No caravan connected
When reverse is activated power goes through Relay 1 (NC) down to A does not activate Relay 2 as the caravan is not connected, but is looped to the contacts of the relay and supplies power to B which then supplies power to the car camera.
This also activates D put this goes no where as it is isolated by the switch.
With caravan connected
When reverse is activated power goes through Relay 1 (NC) down to A and as the caravan connection closes the loop in the connector it activates Relay 2 (NO) and supplies power to C which then activates the caravan camera.
This also activates E put this goes no where as it is isolated by the switch.
Switch in Up position powers the caravan camera all the time
Put the Switch into the up position will via one set of contacts engage Relay 1 and isolate the reversing input so it has no effect.
This will also via the second set of contacts supply power directly to the caravan camera via E.
This will also activate C which is isolated by the Normally Open (NO) contact on relay 2 and relay 2 can not be activated because of A being isolated by relay 1.
Switch in Down position powers the car camera all the time
Put the Switch into the down position will via one set of contacts engage Relay 1 and isolate the reversing input so it has no effect.
This will also via the second set of contacts supply power directly to the car camera via D.
This will also activate B which will via the Normally Closed (NC) contact activate A which will activate the contact of relay 1 but is is isolated by the Normally Open (NC) contact on relay 1 being open as relay 1 is activated.
The line through the middle was my initial cut at dividing the system between front and back of car.
Also you need to determine if the switching for reverse is positive side or negative. This circuit assumes that reverse is activated by the reverse feed going 12V. If the reverse is activated by the reverse feed going 0V (Earth) than you need to change the 12 V Reverse input and the loop ground around.
And finally the video feed would go through a combiner / splitter (passive device) and feed the reverse input for your GPS reversing camera.
Note that I have not installed this and you need to know the reversing polarity of your car, the load that the relays and camera will put on the circuits and that this is acceptable and that the GPS will take the feed over the distance and through the splitter / combiner.
If I implement this then I will be laying it all out prior to installation and connecting it up to make sure it all works. I would then package it all up and check again then install.
This design was more for a single input GPS that detected a video feed on the video input and would switch it in.
There are two options, the second one uses a double pole triple throw (DPTT) switch. The problem with this was that I could not readily find a switch that looked the part and was actually DPTT. They are all On/Off/On which is different.
So a quick how it works (using the first option with two relays:
Switch in Off position gives you automatic reverse, GPS detects video feed and displays.
No caravan connected
When reverse is activated power goes through Relay 1 (NC) down to A does not activate Relay 2 as the caravan is not connected, but is looped to the contacts of the relay and supplies power to B which then supplies power to the car camera.
This also activates D put this goes no where as it is isolated by the switch.
With caravan connected
When reverse is activated power goes through Relay 1 (NC) down to A and as the caravan connection closes the loop in the connector it activates Relay 2 (NO) and supplies power to C which then activates the caravan camera.
This also activates E put this goes no where as it is isolated by the switch.
Switch in Up position powers the caravan camera all the time
Put the Switch into the up position will via one set of contacts engage Relay 1 and isolate the reversing input so it has no effect.
This will also via the second set of contacts supply power directly to the caravan camera via E.
This will also activate C which is isolated by the Normally Open (NO) contact on relay 2 and relay 2 can not be activated because of A being isolated by relay 1.
Switch in Down position powers the car camera all the time
Put the Switch into the down position will via one set of contacts engage Relay 1 and isolate the reversing input so it has no effect.
This will also via the second set of contacts supply power directly to the car camera via D.
This will also activate B which will via the Normally Closed (NC) contact activate A which will activate the contact of relay 1 but is is isolated by the Normally Open (NC) contact on relay 1 being open as relay 1 is activated.
The line through the middle was my initial cut at dividing the system between front and back of car.
Also you need to determine if the switching for reverse is positive side or negative. This circuit assumes that reverse is activated by the reverse feed going 12V. If the reverse is activated by the reverse feed going 0V (Earth) than you need to change the 12 V Reverse input and the loop ground around.
And finally the video feed would go through a combiner / splitter (passive device) and feed the reverse input for your GPS reversing camera.
Note that I have not installed this and you need to know the reversing polarity of your car, the load that the relays and camera will put on the circuits and that this is acceptable and that the GPS will take the feed over the distance and through the splitter / combiner.
If I implement this then I will be laying it all out prior to installation and connecting it up to make sure it all works. I would then package it all up and check again then install.
Nice circuit @millers ....................I just bought 2 x 90 deg cameras, a 2 input screen which goes where the rear view mirror lives and I can switch between either camera , as I have a cab/chassis with a shed on the back the rear view mirror was redundant and the cam takes up the slack and stops me cleaning up objects in car parks, I possibly can record the feed. The 90 deg cams mean I can see whats behind me for a Km or so not just 20 ft like the 120 deg cams.
Love it - to be honest it's over my head but I have a mate who loves this stuff. Will print it out and see what he thinks. Thanks heaps
Wired up the reverse camera on the previous Cruiser through a DPTT switch so it would:
1) Only come on when reverse was selected
and
2) Continuous power supply so it stayed on no matter what gear it was in (I got sick of the screen turning on/off when hooking up the van or boat!)
1) Only come on when reverse was selected
and
2) Continuous power supply so it stayed on no matter what gear it was in (I got sick of the screen turning on/off when hooking up the van or boat!)
Mine is also via a DPDT switch. I took the 12v power for the camera off the 12v supply to the fridge, so whenever the 12 pin is plugged in the camera is powered, so I only needed to run the analogue video from the camera back to the tug and up to the screen at the front.
This is pretty simple, and doesn't require any relays