Control box key:

S1, S2 - subminiature SPST roller lever switch % amps @ 250 vac
S3 - SPST toggle switch
RFC1, RFC2 - axial-lead RF choke, .1mH, 2 amps
R1 - 1/2-watt, 5600-ohm resistor
D1 - 3-amp 200 PIV epoxy rectifier
RY1, RY2 - 10 amp DPDT relay, 12 VDC
RY3 - miniature SPDT relay, 12 VDC
Q1 - FPT-100 silicon phototransistor
C1, C2 - tubular capacitor, .1 MFD @ 200V
SCR - silicon-controlled rectifier, 400 V, 6 amp