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Circuits designed by David Johnson, P.E.
Last Updated on: Friday, December 29, 2017 02:53 AM


Text & Graphics Copyright © David A. Johnson, PE  --  ALL Rights Reserved.
LINKING to Dave's circuits is permitted but COPYING CONTENT to your WEB SITE server IS NOT!


Alarm Circuits
Circuits Designed by Dave Johnson, P.E. :

Fake Car Alarm Light

Fence Alarm

Freeze Alarm

Freezer Over-Temperature Alarm

Freezing Temperature Alarm

Hidden Panic Switch

Human Footstep Alarm

Indicates when it is Time to Dust

Is it Time to Dust?

Light/Dark Activated Motion Detector

Low Voltage 120vAC Power Line Alarm

Micro Power Over-Temperature Alarm

Monitors Pump Motor

Motion Alarm using piezo Device

Power Line Alarm

Power Loss Beeper

Pump Motor Monitor

Remote Doorbell Beeper

Simple Circuit Wire Security Loop Alarm

Star Trek Doorbell

Under/Over Voltage Alarm on AC Line

Unplugged Appliance Alarm

Unplugged Power Cord Alarm

Water Cistern Level Alarm

120 VAC Low Voltage Alarm 

3v Sweeping Siren Alarm

AC Power Loss Alarm

Alarm Beeps when the “Check Engine” Light Turns On

Alarm sounds when Water is Detected

Alarm-Piezo Device Detects Motion

Another Very Loud piezo Alarm Beeper

Bad Light Bulb Indicator

Basement Doorbell Beeper

Chain Link Fence Alarm

Cut Phone Line Alarm

Detects Shadow Activated Motion

Doggie Water Dispenser Alarm

Door Knob Alarm

Door Knock Beeper

Electric Field Disturbance Monitor-Alarm Discriminator + Battery Monitor


 

Dave's Circuits

Hobby Circuits

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Copyright  January, 1998 - December, 2017     David A. Johnson & Associates.  All Rights reserved. 


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