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+12V input?
Posted:
Sun Dec 20, 2020 7:47 pmby greenamex2
Hi all
Anyway of triggering a PDM input of a +12V signal without resorting to a pull down resistor?
Thanks in advance
Re: +12V input?
Posted:
Mon Dec 21, 2020 6:40 amby RR213
When configuring the input pins there is the option for active high or active low. For 12v switched inputs use active high.
Re: +12V input?
Posted:
Mon Dec 21, 2020 6:58 amby greenamex2
RR213 wrote:When configuring the input pins there is the option for active high or active low. For 12v switched inputs use active high.
Unfortunately when no 12v signal is present the source isn't pull to ground so the pdm still gets pulled to +12v anyway by the internal pdm pull-up!
Re: +12V input?
Posted:
Mon Dec 21, 2020 8:20 amby adrian
The PDM switch inputs were originally designed for pull to ground type switching so unfortunately the only way to wire a 12V switch into the PDM is by adding a pull down resistor.
Re: +12V input?
Posted:
Mon Dec 21, 2020 8:27 amby greenamex2
adrian wrote:The PDM switch inputs were originally designed for pull to ground type switching so unfortunately the only way to wire a 12V switch into the PDM is by adding a pull down resistor.
Thanks for confirming Adrian.
I have managed to work how to fit them inside a Rostra cruise control stalk.
Re: +12V input?
Posted:
Sun Jul 03, 2022 6:21 amby Ae92
adrian wrote:The PDM switch inputs were originally designed for pull to ground type switching so unfortunately the only way to wire a 12V switch into the PDM is by adding a pull down resistor.
How would you wire a pull down resistor in please ?
Re: +12V input?
Posted:
Mon Jul 04, 2022 10:14 amby Stephen Dean
Hi,
You need to wire a 1500ohm 0.25w resistor between the Input wire and the 0V wire. The Trigger levels for the input should be set to 4V and 5V for correct triggering.
Re: +12V input?
Posted:
Sat Jul 23, 2022 6:57 amby Ae92
SDean wrote:Hi,
You need to wire a 1500ohm 0.25w resistor between the Input wire and the 0V wire. The Trigger levels for the input should be set to 4V and 5V for correct triggering.
Thanks mate
I was going to wire 12+ ignition switch to my pdm30 if I was to add a pull down resistor would I still be able the use accessories still wired to the ignition switch ? (I have my alarm system still wired to my ignition switch)