Page 129 - Doctor Who

Low Power Solenoid Circuit
Drive
:- -P~~er-D~I;e;B-o;rd - - - - - - - - - - - - - - - - - - - :
I
vee
J127' , or
_,--+---IX ' 8ackbox Coli ,
, Brown-xxx
A
Power
+50V
P/ayf/e/d
I- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ~
The microprocessor toggles the output of the 74LS374. When point "A" is low, point "8" the collector of the 2N5401 transistor is
driven high. A high at point "8" turns On the TIP1 02 transistor and causes point "C" to drop low. When point "C" is low the coil is
grounded through the transistor and the coil turns On. ,The coil shuts Off when point "A" toggles high.
Drive
v - Po~;rDrlv;r B~a;d- - - - - - - - - - - - - - - - - - - - t
Flashlamp Solenoid Circuit
A
Power
,
J125,
1__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Flash/amp
Black-xxx
Red-White
The microprocessor toggles the output of the 74LS374. When point "A" is low, point ".8" the collector of the 2N5401 transistor i~
high. Once point "8" is high, point "C" the collector of the TIP102 transistor is low. When Point "C" is low the flashlamp ls
grounded through the transistor and the flashlamp turns On. When point "A" toggles high the circuit shuts Off.
DOCTORWHO 3-6