TM-9-1200-215-34&P Technical Manual for M109 Automatic Fire Control System (AFCS) Download
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TM 9–1200–215–34&P 6–4 b. Physical description. The PCU consists of a single, sealed, enclosure which contains the following components: D Eight (8) connectors (J1–J8) D Circuit breakers D Transient voltage suppressors D EMI Filters D Power–up relays D Input power loss support circuit D Back–up battery charger D Status monitors circuit D Nuclear event detector (1) Eight connectors. As shown in figure 6–2, 28 Vdc vehicle power enters the PCU on connector J4. Back–up batteries are connected to the PCU on connector J3. Connector J5 is the diagnostic port connection to the PCU. Power is distributed from the following indicated connectors: D J1, J2 – Dual power bus to the: •• Display Unit (DU) •• AFCS Computer Unit (ACU) •• Prognostics/Diagnostics Interface Unit (PDIU) D J6 – Outside Component D J7 – Outside Component D J8 – Outside Component PCU J6 J7 J8 J5 J3 J4 (–) A (–) 28V CONDITIONED DISCRETE SIGNALS 28V CONDITIONED CONDITIONED RETURN DISCRETE SIGNALS 28V CONDITIONED CONDITIONED RETURN CONDITIONED RETURN 28V CONDITIONED 28V UNCONDITIONED 28V UNCONDITIONED J1 BUS A J2 BUS B DIAGNOSTIC PORT B BACKUP BATTERY (+) BACKUP BATTERY (+) VEHICLE 28V 28V RETURN CONDITIONED RETURN UNCONDITIONED RETURN 28V CONDITIONED CONDITIONED RETURN UNCONDITIONED RETURN Figure 6–2. PCU Power Distribution