Lee Campbell 8 26 07

Fuse Holder and Sensor line with 1 Amp Circuit Breaker

Each battery [See Figure above.] has 2 sets of 2 sensor lines, one for the positive terminal and one for the negative terminal, connected through a 1 amp resetable circuit breakers. Two wires to each battery terminal are used for the possible future implementation of a cable check function. These wires are connected though a 25-pin-connector sense-line cable and a ribbon cable to the switching logic board.

Battery Cabling Set

The 144v battery pack is divided into 3 sets of eight - 6 volt batteries with a sense-line cable fanned out to the 8 individual batteries of the set. The enclosure also contains a wireless camera for projection the meter assembly readings to the cab display and the hand held monitor.

Circuit Board with 3 Cables

The switching logic circuit board receives the 6 volt battery sense line input through the 3 ribbon cables corresponding to the three sets of eight batteries. Each battery has a corresponding DPDT relay that has the battery's voltage  constantly felt at the center taps of the relays. Sequencing logic on the circuit board energizes each of the relays in a set of eight relays 1 through 8. [Note. There is a zero count discussed later.] Therefore, three batteries are monitored at the same time with three different meters. Starting with battery 1 in each set of eight batteries the relays are simultaneously energized for 4 seconds then de-energized. Then battery 2 in each set of eight batteries the relays are simultaneously energized for 4 seconds then de-energized, etc., until the eighth relay feeling the eighth battery in set of eight batteries is energized. When a battery relay is energized the normally open poles of the relay is closed transferring the 6 Volt battery sense line voltage to these poles. For each set of 8 batteries/relays there is a single meter used for monitoring. The normally open pools of the eight relays of a set are tied to the sense input of the meter. Since only one relay in a set of 8 is energized at one time the meter will read only one voltage at a time. The two other meters are connected identically to read the voltage from the other two sets of eight 6 volt batteries. A delay of 4 seconds has been implemented between counts to allow for switch bounce and meter reading stabilization.

Three Meters

The meter circuit board houses the three meters that convert the analog input from the switching logic circuit board via a single ribbon cable. This circuit board also has a single 7-segment display to identify which battery in each set is being monitored. The meters are powered by individual dc-dc converters with transformer isolation. The 7-segment battery counter actually counts starting at zero. During the zero count the meters monitor the solar panel output voltage, the 5 volt logic supply and an 8-volt wireless camera supply.

Voltage Monitor Circuit Diagram

Cab Display

This cab display is showing the values for the 5th battery in each set of 8 batteries or battery 5 in the first set, battery 13 in set 2, and battery 21 in set 3.

Hand Held Monitor

This hand held display is showing the '0' count and is monitoring from top to bottom, the 8 v logic supply, the 5 v camera supply, and the solar panel system output .