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DS40160A/3_022-page 3-15

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Low Cost Iron Safety Timer

INTRODUCTION

Clothes irons and curling irons are high powered appli-

ances that can start house fires. Many times after leav-

ing for work you forget if you shut-off or unplug the

dangerous appliances. This timer will allow the appli-

ance to have power for only a fixed amount of time

(without motion/use). Then it will shut-off power. A reset

switch will restart the appliance.

FIGURE 1:

FLOWCHART

FIGURE 2:

SCHEMATIC

Author:

Jason Wolfson

Lipider Corp.

Duxbury ,MA

USA

email: jason@ultrnet.com

Decrement time

Time-out?

Power-up

Turn on Triac

Turn off

Check switch?

No

Yes

No

Yes

Zero Detect?

No

Yes

PIC12C508

Load

Vcc

GP2/TOCKI

GP3

GP1

SIMPLECIRCUIT™