BENDIX BW1594 Manuel D’Utilisation

The Bendix

®

 SL-5

™

 stop light switch is an electro-pneumatic

5 psi non-grounded switch that operates in conjunction with
the brake valve and stop lights by completing the electrical
circuit and lighting the stop lights when a brake application
is made.

The DS-2

™

 combined stop light switch and double check

valve, as the name implies, combines a SL-5

™

 stop light

switch with a DC-4

™

 double check valve to perform the

function of both. It operates in conjunction with the brake
valve and hand control valve by directing the flow of air from
whichever delivers the higher pressure into a common delivery
line and to the stop light switch, closing the electrical circuit
to the stop lamps.

The stop light switch can be used with either 12 or 24 volt
systems.

The stoplight switch is not a serviceable item; and if found
defective in either device, the complete unit must be replaced.

The shuttle valve in the DS-2

™

 valve is serviceable and may

be replaced.

Both the SL-5

™

 switch and the DS-2

™

 valve have been tested

and meet the requirements of FMVSS 121.

The stop switch mechanism is identical in the SL-5

™

 switch

and the DS-2

™

 valve.

When a brake application is made, air pressure from the
brake valve enters the cavity below the diaphragm. The air
pressure below the diaphragm moves the piston until it
contacts the leaf spring. The leaf spring travels past a fulcrum
at which point the leaf springs snaps a shorting bar which
mates with the contact strips. The stop light electrical circuit

DS-2

™

VALVE

SL-5

™

STOP

LIGHT

SWITCH

FIGURE 1 - DS-2

™

 COMBINED STOP LIGHT SWITCH & DOUBLE CHECK VALVE SECTIONAL

RIVET

INLET PORT

INLET
PORT

CONTACT

STRIP

FULCRUM

SHORTING

BAR

TERMINAL

OUTLET PORT

LEAF

SPRING

PISTON

DIAPHRAGM

SHUTTLE

VALVE

(CHECK

VALVE)