Model 333SingleChannel USBChromatography
DataSystemRelay ( Contact Closure ) Installation
Remove the four screws holding the
Model 333A/Dboard in the stand-alone
box.
If the333 is installed inaGCorHPLC,
remove the four hex head screws from
theoutsideof the instrument which se-
cure the333board to the insideof the
chassis. This requires a9/32” allen
( hex ) wrench.
The fourmechanical singlepoledual
throw ( SPDT ) relaysmust be soldered
into the board in the lower right hand
corner of the333board. Each relay is
ratedat 24voltsDCand1amp. For
most handshaking applicationswhere
the relay is used toactuateaValco
valve for example there is very little cur-
rent ( often referred toasa contact clo-
sure ).
Youwill need the followingparts:
FourSPDT relays
Four 2N3904 transistors
Four 10,000ohm resistors
Four 3position terminal blocks
Four whitewires
Heat shrink tubing
One redwire
Oneblackwire
One7812 voltage regulator
One10uf capacitor
One .01uf capacitor
Theseparts areavailableas a kit from
SRI under part#8600-1051 $149.00
Model333
Relay Installation
Page 1
The four relays are soldered
into the holes in this area
