Claims
- 1. A battery condition indicator for use in a circuit comprising a DC power supply connected across the terminals of a nickel cadmium battery, comprising:
- (a) a first main branch leading to the positive side of the power supply;
- (b) a second main branch leading to the negative side;
- (c) four transistor circuits connected in parallel with said positive main branch and each including a transistor, the four circuits and transistors being herein designated 1 to 4, the fourth transistor in the series 1 to 4 having its emitter connected through a circuit with the negative main branch of the DC current source;
- (d) a connection from the negative emitter circuit of the fourth transistor to the base of the first emitter, said connection including a resistor;
- (e) the second transistor having its base connected with the collector-to-green LED circuit of the first transistor;
- (f) a zener diode having a connection from the negative emitter circuit of the fourth diode through said zener diode with the base of the first transistor with a resistor between the zener diode and the base of said first transistor;
- (g) a shunt circuit around said last-named resistor wherein the base of the third transistor is connected through a resistor to the connection leading from the zener diode to the base of the first transistor at a point between the zener diode and the resistor in said connection, the collector circuit of the third transistor being also connected to the connection between the zener diode and the base of the first transistor but joining said connection between the said resistor in said connection; and
- (h) the said four parallel transistor circuits as herein defined being thereby so arranged that a normal charging current path will put a negative bias on the base of the first transistor to light the green LED, thereby extinguishing the red, but lighting the red by an absence of adequate negative voltage in the base of the first transistor, and the lighting of the green by the application of adequate negative voltage through the zener diode circuit to bias the first transistor, the green LED being extinguished when the charging voltage is above normal by the positive voltage from the collector of the third transistor offsetting the negative flow from the zener diode, but by reason of the resistor in the connection between the zener diode and the base of the first transmitter enabling the zener diode to continue to supply a negative bias to the base of the third diode.
- 2. The battery condition indicator defined in claim 1 in which a thermistor inversely responsive to temperature is shunted across the emitter and base circuits of the fourth transistor to vary the negative voltage to which the zener diode responds.
- 3. The battery condition indicator circuit defined in claim 1 wherein the red and green LEDs are combined in trichromatic arrangement to produce a yellow light in transition areas where both may be in a borderline state of operation between red only or green only.
- 4. In a battery charging and condition indicator system, a nickel cadmium storage battery, an alternating power source and a rectifier for transforming alternating current to direct current, and positive and negative lines through which direct current is supplied from the battery to an apparatus to which current is ordinarily supplied from the AC source to the rectifier in the event of a failure of the AC source, the improvement comprising:
- (a) a main positive and a main negative line rectifier, the line from the rectifier being divided between the rectifier and the battery terminal into two main divisions, the first of which contains a fixed resistance comprising two sections in series, a normally open circuit comprising a time delay relay which, when the relay is energized, shunts out one of said two fixed resistances;
- (b) a shunt circuit around said two fixed resistors which, along with the main negative line from the rectifier, lead directly to the respective positive and negative terminals of the battery through a voltage regulator, there being a diode in the positive line between the battery and the voltage regulator or the fixed resistors, the effect of which circuits is to connect the storage battery is parallel with the load instead of in series when said relay is energized.
- 5. In a battery charging system comprising a rectifier for converting alternating current to direct current and a battery having a positive pole connected with the positive terminal of the rectifier through a main line and having its negative terminal connected through a main line with the negative terminal of the rectifier, the improvement wherein:
- (a) the positive line connecting the battery and the rectifier has a diode near its battery terminal preventing any reverse flow of current from the battery into said line, the line having two resistors in series between its ends with the two resistors both normally in the conducting length of the line between the rectifier and the diode;
- (b) a shunt circuit around one of said resistors and the said positive line and the input terminal of the diode, said circuit including means for variably and intermittently withdrawing electrical energy from said line and, when so doing, it shorts out one of said series of two resistors; and
- (c) a second shunt circuit in the positive line around both resistors and, parallel with a negative line, both passing through a voltage regulator, the negative line continuing to the battery terminal, the battery in effect being then connected in parallel with the load represented by the said means for variably and intermittently withdrawing current from the battery, while said voltage regulator shunted around the load maintains a generally constant potential at the positive terminal of the battery.
- 6. In the battery charging circuit defined in claim 4, the combination wherein the shunt circuit around one of said two resistors comprises TDR-1 of a pump protective circuit and a ground circuit whereas the circuit from the positive pole of the battery is through TDR-2 of the same pump protective circuit to ground.
- 7. In the battery condition indicator circuit defined in claim 3, the main positive conductor into which Z is connected is that part of the circuit between the rectifier positive terminal and the two resistors and said shunt circuit and the main negative line is between the rectifier negative terminal and the battery.
Parent Case Info
This is a division of application Ser. No. 948,040 filed Oct. 2, 1978 now U.S. Pat. No. 4,273,513.
Divisions (1)
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Number |
Date |
Country |
Parent |
948040 |
Oct 1978 |
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