CHAPTER 4 FUNCTIONING OF EQUIPMENT - TM-5-6350-262-14-80018

TM 5-6350-262-14/8

NAVELEX 0967-LP466-9081

TO 31S9-4-31-1 Chg 1

CHAPTER 4

FUNCTIONING OF EQUIPMENT

4-1. Mechanical Functions

assembly. The contacts of this switch are held closed

by a projection on the cover of the assembly.

a. The balanced magnet switch operates on the

Whenever the cover is removed, the switch contacts are

principle that if opposing magnetic fields imposed on a

opened (tamper condition).

reed switch are cancelled, the switch will remain

unactuated. Likewise, if the magnetic fields become

unbalanced, the reed switch will actuate. The system of

4-2. Electrical Functions

magnets of the balanced magnetic switch consists of the

a. The operational schematics of the switch

two magnets (16, fig. C-1) in the magnet assembly and

assembly are shown in figure 4-1. Figure 4-1A shows

the bias magnet assembly (9, fig. C-1) in the switch

the circuit condition of the balanced magnetic switch

assembly. Without the presence of the biasing magnet

whenever magnetic switch S2 is unactuated. In this

in the switch assembly, the reed switch (S2 in figure 2-2)

condition, TB1-1 and-2 is a closed circuit with a

would always be actuated whenever this assembly was

resistance of 50 ohms, and TBL-1 and-7 is an open

near the magnet assembly. However, the biasing

circuit. This condition is interpreted by the J-SIIDS as a

magnet is capable of balancing out the effects of the

secure condition.

magnet assembly when properly adjusted, to allow the

b. Figure 4-1B shows the configuration of the

reed switch to remain unactuated even when in close

balanced magnetic switch whenever magnetic switch S2

proximity to the magnet assembly.

is actuated. In this condition, TBL-1 and -2 is an open

b. The system of magnets is designed such that

circuit and TB1-2 and -7 is a closed circuit with a

whenever the magnet assembly is moved a specified

resistance less than 50 ohms.

This condition is

distance away from the switch assembly, the field of the

interpreted by J-SIIDS as an alarm condition.

biasing magnet is no longer balanced out by the magnet

c. Figure 4-1C shows the configuration of the

assembly and the biasing magnet causes the reed

balanced magnetic switch whenever the cover has been

switch to actuate. The balanced condition can also be

removed. In this condition TB1-5 and -6 is an open

upset if another foreign magnet is brought into proximity

circuit. This condition is interpreted by J-SIIDS as a

with the switch assembly.

tamper condition.

c. A microswitch (S1 in fig. 2-2) is also provided to

detect the removal of the cover of the magnetic switch

4-1