BY AL JASZEK
Power ON/OFF Switch
of A/C Controller
■ FIGURE 3. End view showing the
power switch and the power cord.
I obtained the following materials:
• An aluminum project box — 5 x 4 x 3
• A relay whose A/C contacts were rated ■ SCHEMATIC 1
at or about 10 amps and with a coil
voltage of 24 VAC.
• A sub-miniature single pole single throw
• A power on/off switch rated at 125
VAC and 10A. ■ FIGURE 4. Interior view of the controller
• A transformer for converting line showing the wiring.
voltage to 24 VAC.
• A six-foot A/C extension cord.
• An AC receptacle.
• Miscellaneous hardware including wire,
terminal strips, nuts and bolts, and
Connection for Thermostat
I had disassembled. The 24 VAC
transformer was from an old oil-burner
controller. The relay was one of many
I had in my spare parts bin, and so on.
■ FIGURE 5. Opposing interior view of
the controller showing the wiring.
I am not detailing the parts I used,
as most had been recycled. For
example, the power on/off switch
was taken from an old computer
■ FIGURE 6. View of the controller in use.
■ FIGURE 7. Back view of the thermostat showing how it was
mounted to an aluminum bar for stability.
March 2007 49