Mainstay power requirements

[Jaggermax]

This post is to help those of you wanting to hook up a Mainstay sensor to a microcontroller based circuit, or even a descrete timer circuit. ###I have been attempting to hook up the Mainstay trigger line to the input of my controller. ###I am running both the controller and the Mainstay off of a LM3117 5 volt regulator which is powered from four AA batteries. The only reason I am using the 5 volt regulater is because of the in circuit programmer which requires 5 volts from the board. But guess what. ###The Mainstay oscillates the trigger line at anything under 4.8 volts input power. ###

Also, to interface the Mainstay, I hooked up the power and ground wires as normal, but for the trigger line, I hooked up to the sinking leg pad where the relay was removed (the one near the top of the board) and activated the pull up input port resistor. ###When activated by the motion sensor, this line goes from +5V to 0 Volt (with pull up resistor)

Anyway, there are three options you can use to hook up the Mainstay. ###1) go with a low dropout regulator which will keep the voltage near 5V longer as the batteries wear down 2) Use a seperate 9 volt battery to run the Mainstay with the ground tied to the board and 3) which is what I did, just run power directly from the output from the batteries (6.5 volts)to the power on the Mainstay while still using the regulator to power the board. ###Hope this helps. ###




(Edited by Jaggermax at 11:54 pm on Jan. 20, 2002)

[Tinhorn]

Jaggermax

The MS20 power source (battery) can be 6 - 24vdc, it has an internal 5v voltage regulator (off of C5 (+) (220uf). ###Why can't you run your micro-controller off the MS20's internal 5v regulated supply? ### ###

I don't know hou much current it will provide but I bet it will drive your micro-controller as long as the Relay Coils are wired up to the raw battery source and are driven by transistor relay drivers (driven by your Micro-Controller)

also, the Output (Pin 14) of the MS20 goes from 0 to 5volts when triggered, won't this work?

I drew up a schematic of the MS20 if you need it....

Tinhorn

[Jaggermax]

I measured the output pin 14 and it was only 3.5 Volts. ###However, that was with using the 5 volt regulator on my board to power it. ###I guess that is all you get when supplying 5 volts. ###I did not know it had a built in regulator on the RS board. ###Great idea to run the controller off of that power supply. ###I am drivin the relay with a darlington array and I will try connecting the power rails of the chip to the battery directly. ###I found you schematic and am going through it now. ###Thanks for the ideas! ###

[upnorthunter]

where are the mainstays still available to by?

[Tinhorn]

Our Wally World still has some I think, here in Missouri, at least I hope they do

[STR8SHTR]

they must have heard about Hamiltoe and his operation

(Edited by STR8SHTR at 5:05 pm on Jan. 22, 2002)

[upnorthunter]

can you use these pir's with hamiltoes boards?

[Tinhorn]

Jaggermax

In case you didnt fine out by now, I was WRONG about pin 14 going to the full 5volts, it's only 3.75 on my Test MS20 and your 3.5v measurement was right after all, ###Sorry

Tinhorn