15 



(1) 220 ohm resistor, V2 watt, 5% tolerance 

 (1) 470k ohm resistor, ^2 watt, 5% tolerance 

 (1) electrolytic capacitor, 500 uf 0-25 DC 



(1) unijunction transistor ECG6401 (GTE Products Corp., Wal- 

 tham, Massachusetts 02154) 



(2) brass bolts 



Instructions (refer to Figs. 6, 16) 



1 , Solder the electrical components to the circuit board (Fig. 6). 

 NOTE: Be careful not to overheat the unijunction transis- 

 tor when soldering, as it may be damaged by very 

 high temperatures. 



2. Drill and tap two holes in the rear of the plexiglass stage and 

 bolt the circuit board to the stage (Fig. 16). 



Mounting and Wiring the Unijunction Accelerator Switch 



Materials 



(1) SPDT momentary spring-return switch, 6A, 125 VAC 



(1) 4.7k ohm resistor, V2 watt, 5% tolerance 



(2) 10 cm length of 18 gauge single-conductor wire 



Instructions (Refer to Figs. 6, 16) 



1. Mount the momentary spring-return switch on the plexi- 

 glass stage (Fig. 16). 



2. Solder one end of a 10 cm length of 18 gauge wire to the 

 positive end of the electrolytic capacitor, and solder the other 

 end to the 4.7k ohm resistor. 



3. Solder the resistor to the center pole of the momentary 

 switch (a. Fig. 6). 



4. Solder one end of a 10 cm length of 18 gauge wire to the 

 junction of the 220 ohm and 470k ohm resistors (b. Fig. 6), 

 and solder the other end to the (normally open) pole of the 

 switch (c. Fig. 6), 



Wiring the Unijunction Assembly to the LWI Pen Arm Relay 



Materials 



(2) 15 cm length of single-conductor 18 gauge wire 



Instructions '(refer to Fig. 6) 



1. Solder one end of 18 gauge wire to one of the prongs on the 6 

 V LWI relay, and solder the other end to prong Bg of the 

 unijunction transistor. 



