Circuit designer
Budget: $30 – $250 AUD
Hello, I need some help to design a circuit that will allow me to utilise my car stereo/headunit in a couple of more modern ways outlined below.
with a standard Headunit it runs off switched and constant power. to my understanding the constant wire is there for memory and the switched power runs from ignition position.
What I'd like is a circuit that would have an input for the constant, switched and earth - as well as a signal input from the door sensor. then output constant and switched.
I'm looking to achieve the following:
Allow the unit to stay on during cranking - most cars the unit won't have enough reserve power to stay on while cranking meaning it restarts, disconnecting bluetooth etc. I was thinking to use a small bank of capacitors or other solution which would keep it on for the 5secs or so of cranking - I was thinking if the box can utilise the constant wire it could charge the capacitors while the car is off/no ignition - so when it cranks the power is already there but not sure if this would cause a parasitic draw.
Once the key is removed from the ignition have power continue to run through the headunit until either: 2mins has elapsed or the door is opened. I was thinking this could run on a timer circuit and also the input for door sensor would allow it to cut power before 2min has elapsed if the drivers door is opened.
I would like to keep it fairly modular, so the end user can install on most cars - so an input and output for both power switched and constant - and a signal input from the door sensor can be connected to the circuit via screw terminals or similar
A nice bonus but definitely not nessecary would be an adjustment for the timing part of the circuit, but I feel 2min is adequate.
I'm definitely not a designer but I hope this makes sense. if It could use mostly off the shelf components that'd be great, just so I can build it myself :)
with a standard Headunit it runs off switched and constant power. to my understanding the constant wire is there for memory and the switched power runs from ignition position.
What I'd like is a circuit that would have an input for the constant, switched and earth - as well as a signal input from the door sensor. then output constant and switched.
I'm looking to achieve the following:
Allow the unit to stay on during cranking - most cars the unit won't have enough reserve power to stay on while cranking meaning it restarts, disconnecting bluetooth etc. I was thinking to use a small bank of capacitors or other solution which would keep it on for the 5secs or so of cranking - I was thinking if the box can utilise the constant wire it could charge the capacitors while the car is off/no ignition - so when it cranks the power is already there but not sure if this would cause a parasitic draw.
Once the key is removed from the ignition have power continue to run through the headunit until either: 2mins has elapsed or the door is opened. I was thinking this could run on a timer circuit and also the input for door sensor would allow it to cut power before 2min has elapsed if the drivers door is opened.
I would like to keep it fairly modular, so the end user can install on most cars - so an input and output for both power switched and constant - and a signal input from the door sensor can be connected to the circuit via screw terminals or similar
A nice bonus but definitely not nessecary would be an adjustment for the timing part of the circuit, but I feel 2min is adequate.
I'm definitely not a designer but I hope this makes sense. if It could use mostly off the shelf components that'd be great, just so I can build it myself :)