A.C.-D.C. SPIKE ELIMINATING BANDPASS FILTER

Abstract: The field of the invention deals with lightning, AC and DC voltage transient spikes. Due to activation time and cut-off frequency, previous devices have been unable to remove these spikes from the power lines fast enough to prevent damage. The present invention solves this problem by using elements (4), (C5), (L6), (C7) in line between a voltage source and load. The present invention is being used in the field of telecommunications, commercial and industrial controls and the computer field.

Description: A.C.-D.C. SPIKE ELIMINATING BANDPASS FILTER B. Cross-References to related appl icati ns: Bl . Crosby et. al . Patent Number 4,584,622 Apr. 22, 1986 B2. 4,152,743 5/197? Constock 361/11 IX B3. 4,259,705 3/1981 S i-fter 361/56 D. BACKGROUND OF THE INVENTION 1. Field o-f the Invention: This invention concerns the el imination o-f voltages not in the Bandpass o-f the -filter, A.C. or D.C. voltages. The prol i eration in the use of integrated circuits in home controls and electronics, telecommunications, commercial and industrial controls, and the computer field has resulted in the desirabil ity of a circuit that will el iminate transient spikes and suppress over-voltages that destroy IC's. This invention provides such a circuit. It also has the capabil ity of passing audio, Tip and ring voltages, data transmission and touch tone frequencies for both the input phone l ines and the output phone l ines and remotes of a PBX and other systems. The circui removes over-voltages caused by l ightning strike and man-made equip ent. 2. Background Art: Crosby et, al . util izes a series tuned circuit comprised of 2 capacitors 5 it 6 and 2 inductors L7 Sc L8. A series tuned circuit has a low r Q of resonance and a wider Bandpass than the P ϊ Network used in our circuit, w ich demonstrates a high Q and sharp slopes to cutoff out of Bandpass voltages. To bleed-off the ovei— oltage we use a minimum of 4 caps and 2 inductors, MOV's and gas charge tubes as vol age reducers. There is no need for current l imiting as the load will only pull the current consumed normal ly. SUM-WRY: Our high Q, narrow Bandpass filter acts as a spike eliminator o-f l ightning strike spikes which have higher frequency components. The gas discharge tube voltage l imiters and MOV's reduce the vol age leveT required to protect our bypass capaci ors from over-voltage. As a practical matter, a Micro¬ second C10-6) is about the best response time achievable with known transient surge suppression devices which includes gas discharge tube, MQV's, Zener diodes and other solid state devices. The Bandpass Filter stops vol ages out of Passband frequencies. This prevents spikes from reaching the load. The Bandpass Filter's high impedence stops the transient spike to allow the voltage rise and removal of the over—vol tage by the MOV. The MOV operates at 121 above normal l ine voltage. Our capacitors are set up -for voltage rise to the MOV activation plus a safety margin. This insures repeat performance and longer circu it 1 ife. BRIEF DESCRIPTION OF THE DRAWINGS: FIG 1 is a circuit schematic showing one embodiment of the fixed, portable and mobile protection circuit of the present invention; FIG 2 is a circuit schematic of an embodiment of a fixed 230 VAC 3 phase protection circuit of the present invention; FIG 3 is a circuit schemati of an ebodiment of a fixed 408 VAC 3 phase protection circuit of the present invention; FIG 4A is a circuit schematic of an embodiment of a fixed secondary protection circuit of the present invention; FIG 4B is a construction schematic of the service entrance and meter socket mounting system of the protection circuit of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT: Referring to the drawings wherein l ike reference characters are used for l ike parts throughout, there is illustrated in FIG 1 a 117 VAC 1 phase l ive l ine with bare wire ground and LI & L2 supply A.C. voltage. Connected in seri s with LI is a circuit breaker CB12 rated for load limit. A MOV 4 limits voltage. Capacitors C-5 & C-7 with inductor L6 form a Bandpass filter that prohibits passage of spikes. A resistor R12 and LED D13 form indicating circuit, Leg 2 the return l ine is a dupl ication of Line 1 less the indicating circuit. Capacitors CIO i C8 with inductor L9 form a Bandpass filter. All MOV's and capaci ors go to ground with inductors in series with l ine to form Bandpass filter. Values determine cutoff of frequency Bandpass filter. .- i FIG 2, a 230 VAC 3 phase live Tine Legs 1, 2 & 3 with common l ine ground and also an earth ground. Each l ine leg has a igh voltage gas tube GT 1 voltage l imiter to ground a M0V2 to ground rated at the nearest voltage above the actual l ine voltage of LI, L2 & L3 to further l imit voltage. 2 capacitors C3 & C5 to ground with L-4 inductor in series with line form Bandpass Filter to prevent spike passage that is not in the Bandpass. A circuit breaker C8-8 in each l g to limit oad as rated. FIG 3, a 408 VAC 3 phase He up 1 ive 1 ine, Legs 1,2,3 & 4 wi th common l ine ground and also an earth ground. Each line leg has a high voltage gas tube GT1 voltage l imiter to ground. A MOV 2 to ground rated at the nearest voltage above the required operating vol age of the l ine. 2 capacitors C-3 & C-5 to ground with inductor L-4 in series with line form Bandpass filter to prevent spike passage that is not in the Bandpass. Circuit breaker CBS limits load as rated. FIG 4 A, a 220 VAC 1 phase live l ine, Legs 1 4 2 wi th common plus a driven earth ground of 10' connected with #4 sol id copper wire connecting the two. Leg 1 consists of same circuit components as the circuits in FIG 2 and FIG 3 with the exception of circuit breakers. They are required in the main circui breaker box, i.e., 100A, 200A, 30QA, etc., justifying the removal from our circuit. FIG 4B, a 230 VAC to 480 VAC or more 1 or 3 phase outdoor secondary connecting system with meter socket and protection circuit. Components are same as FIG 2, 3, and 4A. All figures show LED and resistor combination to indicate presence of voltage. Capacitors are oil filled, non-polarized for extended l ife and if needed greater tolerance of over-voltage and heating.

Claims: I Cl im: 1. A voltage spike e iminator for A.C. or D.C. power l ines comprising a circuit comprising: an input consisting of hot lines, common and/or earth grounds; a first gas tube and/or varistor connected between the line and ground; a first capacitor connected between l ine and ground; a first inductor connected in series with the line a second capacitor connected between the line and ground. 2. The spike eliminator of claim 1 wherein the circuit includes a light emitting diode indicates when electrical power is supplied to the input. 3. The spike el imination of claim 1 wherein the circuit includes a circui breaker protection in series with the 1 i e 1 ine.

Inventors: KITCHENS WILLIAM B, KITCHENS, WILLIAM, B.
Applicants: KITCHENS WILLIAM B, KITCHENS, WILLIAM, B.
Application year: 1987
Main classification: H02H3
IPC codes: H02H9