Thread: Reminder beep for Maxi Drive locker

The simplest solution to your concern would be a mechanical interlock to prevent accidental operation of the switch - the so-called missile switch. It depends on whether it's convenient to mount such a switch of course.

You can find the toggle covers online at Altronics http://www.altronics.com.au/index.asp?area=prod&grp=302. You're looking at about $3.50 for a switch and about $6 for the toggle cover. They have water-proof boots for the switches as well which is usually a good idea in a Landy.

Alternatively you can quieten one of the squawking alarms by putting a resistor in series with the +12V feed to it. Altronics have Piezo buzzers on line at http://www.altronics.com.au/index.asp?area=prod&grp=214 (at around $3 to $5).

Their S6100 model produces 75dB of level at 20cm - using a tone of around 400Hz which shouldn't be too annoying. It draws 25mA at 12V. Using R = V / I, the resistance of the buzzer is 12V / 0.025A or 480Ω. To reduce the voltage on the buzzer to half the (nominal) 12V vehicle supply would require a resistor in series of equal value - the nearest preferred value for resistors is 470Ω.

This will reduce the current drawn by half (to 12.5mA) as well and the power dissipated in the resistor, from P = V x I will be 6V x 12.5mA or 0.075W so a half-watt resistor of a value of 470Ω would be more than adequate. You could get a selection of resistors to try in case it's too quiet - say 330Ω, 220Ω, and 100Ω which would give you a few options.

Without giving you the whole lesson on Ohm's Law this should give you a pointer on how to estimate what size resistor would muffle the buzzer.

Jaycar have similar items at similar cost by the way (but a bit less info online). Their buzzers draw 15mA to 25mA so similar resistor values would be in the right ball-park.

Just fit a led to the original warning lighght and put it in view of the driver as a buzzer or beeper will just pi55 you off when ya have the maxi on for long periods i know if somthing was constantly beeping at me to tell me somthings on id be lookin for the hammer to fix the beep