[Amps] Switch Help Needed

[Steve Katz]

Why not use a regular microswitch and float like they do in dishwasher
basins?  Readily available from appliance parts stores for a few bucks...of
course you do need to install some sort of bracket in the tank to hold the
float/switch.

A "water" sensing switch could otherwise be pretty easily made by using a
high-gain saturated op-amp, with two prods spaced 1/2" apart.  Unless you
use de-ionized water, which doesn't conduct, regular (tap/city) water is
miniral-rich enough to cause the amp to take off.  Seems simple,
electrically, but again, you'd need some way to hold the probes/prods or
whatever in place.

WB2WIK/6


"If everything seems under control, you're just not going fast enough." -
Mario Andretti

> -----Original Message-----
> From:	Phil Clements [SMTP:philk5pc@tyler.net]
> Sent:	Thursday, January 02, 2003 10:39 AM
> To:	amps@contesting.com
> Subject:	[Amps] Switch Help Needed
> 
> Pardon the off-topic bandwidth, guys, but there are so
> many resident parts-savvy folks here that might have a source
> for me.
> 
> I am in need of some switches that actuate when immersed
> in water. I am building some quantity indicators for the water
> tanks on the fire trucks @ my local fire dept.  I want to rig
> a light/alarm when the water level drops below a set value.
> 
> Any ideas out there?
> 
> Thanks,
> Phil, K5PC
> 
> Clements Communications and Fire Equipment
> 410 VZ CR 4903
> Ben Wheeler, TX 75754
> (903)852-5211
> 
> 
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