C
CampinGazz
Guest
i am building a motorhome that will have lights controlled by remote
controll, this needs a slave module that's usually just a relay board, that
takes the inputs from the remote reciever, and uses the relays to turn the
loads on or off as needed,
that's fine in a home situation when mains power is available, but i'm
building the van to get maximum run time from the batteries, so having upto
16 relays who's coils pull about 180 milliamps each is not good for power
economy.
The lamps i'll be switching will be LED clusters and CCFL tubes, so the led
clusters pull about 50 milliamps max, and the ccfl tubes inverters about 700
milliamps.
surely it's easy to use a transistor or 2 to turn these loads on and off,
and thus save a lot of unnecessary power running the switches.
it there a single transistor that can be wired and used like a relay? i.e a
input signal of 12 volts, through the transistor to earth, switches the load
through the other 2 pins to turn the load on or off,
or do i need to build a circuit with a couple of trannies? if so what do i
need to do,
i've found a circuit that uses a bipolar npn transistor to turn a relay's
coil on and off, presenting a 0.005 amp load to the switch that's turning
the relay on, but to do this the transistor switches the coil to earth, this
would mean the lights need power to them all the time.. even tho the circuit
is broken untill the transistor turns it on, i dont want that,
i need to be able to switch the positive supply to the lights, how can i do
this easily with a transistor?
controll, this needs a slave module that's usually just a relay board, that
takes the inputs from the remote reciever, and uses the relays to turn the
loads on or off as needed,
that's fine in a home situation when mains power is available, but i'm
building the van to get maximum run time from the batteries, so having upto
16 relays who's coils pull about 180 milliamps each is not good for power
economy.
The lamps i'll be switching will be LED clusters and CCFL tubes, so the led
clusters pull about 50 milliamps max, and the ccfl tubes inverters about 700
milliamps.
surely it's easy to use a transistor or 2 to turn these loads on and off,
and thus save a lot of unnecessary power running the switches.
it there a single transistor that can be wired and used like a relay? i.e a
input signal of 12 volts, through the transistor to earth, switches the load
through the other 2 pins to turn the load on or off,
or do i need to build a circuit with a couple of trannies? if so what do i
need to do,
i've found a circuit that uses a bipolar npn transistor to turn a relay's
coil on and off, presenting a 0.005 amp load to the switch that's turning
the relay on, but to do this the transistor switches the coil to earth, this
would mean the lights need power to them all the time.. even tho the circuit
is broken untill the transistor turns it on, i dont want that,
i need to be able to switch the positive supply to the lights, how can i do
this easily with a transistor?
