CA1111497A - Dual rate voltage regulator - Google Patents

Dual rate voltage regulator

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Publication number
CA1111497A
CA1111497A CA319,788A CA319788A CA1111497A CA 1111497 A CA1111497 A CA 1111497A CA 319788 A CA319788 A CA 319788A CA 1111497 A CA1111497 A CA 1111497A
Authority
CA
Canada
Prior art keywords
voltage
switch
generator
output
emitter
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
CA319,788A
Other languages
French (fr)
Inventor
Ralph E. Scheidler
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to CA319,788A priority Critical patent/CA1111497A/en
Application granted granted Critical
Publication of CA1111497A publication Critical patent/CA1111497A/en
Expired legal-status Critical Current

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Abstract

ABSTRACT OF THE DISCLOSURE
A voltage regulator includes a first normally closed swi-tch arranged for releasably connecting the field coil terminal of an engine-driven DC alternator or DC generator to its appro-priate positive or negative output terminal. The first switch is controlled by an electric actuator having an electric cir-cuit arranged for connection across the output terminals of the alternator or generator and is operable at a predetermined lo-wer level output voltage to open the first switch, whereby to limit the output charging voltage to said lower level which is predetermined to effect charging of the battery without signi-ficant consumption of water. A second switch in the electric circuit of the first switch actuator is controlled by an elec-tric actuator arranged for connection across the output termi-nals of the alternator or generator and is operable at a pre-determined higher level output voltage to close the second sw-itch and activate the first switch actuator to open the first switch and reduce the charging voltage to said lower level fr-om said higher level which is predetermined to effect charging of the battery quickly, whereupon charging continues at the lower level until the engine is shut down.

Description

DUAL RATE VOLTAGE REGULATOR
BACKGROUND OF THE INVENTION
This invention relates to voltage regulators for engine-driven DC alternators or DC generators, and more particularly to a voltage regulator which provides two levels of DC voltage regulation.
Conventional voltage regulators control the DC voltage output of a DC alternator or DC generator so as to produce a predetermined rate of charge. This rate of charge is a com-promise: If the voltage is adjusted so as to recharge the bat-tery ideally, the battery gases and consumes water. If the voltage is adjusted so as to avoid gasing and consumption of water, the charge rate is so low that the battery does not ch-arge properly.
The problem presented by this compromise is magnified in the case of the new "maintenance free" batteries, since it A is not possible to have a single regulator setting that will maintain such batteries in short run applications and still not overcharge a conventional battery on long distance runs.
SUMMARY OF THE INVENTION
In its basic concept, this invention provides a yoltage regulator by which an engine-driven DC alternator or DC gene-rator charges, on startup, at a sufficiently high level of vol-tage regulation to afford quick charging of the engine battery 25 to a predetermined level and thereafter to continue charging at said lower level of voltage regulation which is predeter-mined to maintain the battery charge without siginificant gas-ing and consumption of water.
It is by virtue of the foregoing basic concept that the 30 principal objective of this invention is achieved; namely, to ~11497 overcome the aforementioned disadvantages and limitations of prior voltage regulators by providing a dual rate voltage reg-ulator which is operable with all types of conventional DC
alternators and DC generators.
The dual rate voltage regulator of this invention is of simplified construction for economical manufacture and is of rugged design for maintenance free operation over a long service life.
Other advantages of this invention will appear from the following detailed description, taken in connection with the accompanying drawing of a preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWING
The single figure is a schematic electrical diagram of a dual rate voltage regulator embodying the features of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The drawing illustrates a conventional DC generator or DC
alternator 10 which is provided with positive, negative and field coil terminals 12, 14 and 16, respectively, and is driven by a vehicle engine (not shown) by means of a conventional pull-ey and beIt coupling 18. The vehicle battery 20 is connected across the positive and negative terminals 12 and 14 of the generator or alternator, as illustrated, and the voltage regu-lator is electricall~ releasably connected to the generator or alternator, as through a switch 22 which may be the ignition switch of the vehicle engine.
The dual rate voltage regulator of this invention is an integral unit which is provided with positive, negative and ., ~1~14~7 field coil terminals 24, 26 and 28, respectively, which are con-nected to the generating coils and the field coils respectively of the generator or alternator. Conductors interconnect the corres-ponding terminals, with the switch 22 interposed in the conductor connecting the appropriate positive or negative terminals. In the embodiment illustrated, the switch is interposed - 3a -in the conductor interconnecting the positive terminals.
The housing, indicated by the broken line 30, which mo-unts the terminals, confines therein the electrical circuitry making up the dual rate voltage regulator.
An electric switch is provided for interconnecting the field coil terminal 28 and the appropriate one of the positive or negative terminals, herein illustrated as the positive ter-minal 24. In the embodiment illustrated, the switch comprises the collector-emitter circuit of a transistor 32. The collec-tor is connected to the field coil terminal 28 and the emitter is connected through a diode 34 to the positive terminal 24.
The transistor is biased "on" by means of a resistor 36 which interconnects the transistor base and the negative terminal 26, and the diode 38 which interconnects the collector and negative terminal.
The emitter-collector switch of transistor 32 is contr-olled by a switch actuator which includes the base-emitter ci-rcuit of the transistor. The base of transistor 32 is conn-ected to the collector of a second transistor 40 the emitter of which is connected through diode 34 to the emitter of tran-sistor 32. Thus, upon activation of transistor 40 the emitt-ter-collector thereof functions as a switch to connect the ba-se and emitter of transistor 32 together, deactivating the la-~ tter. The base-emitter of transistor 40 is in an electric circuit which is connected across the positive and negative terminals 24 and 26. Thus, the circuit extends from the pos-itive terminal 24 through the emitter-base circuit of trans-istor 40, through zener diode 42 and voltage divider resist-ors 44, 46 and 48, thence through the silicon controlled rec-tifier 50 to the negative terminal 26.
The zener diode 42 is chosen to fire at a predeterminedlower level of voltage which establishes the lower level of voltage regulation. The firing voltage of the zener diode is established by adjustment of the voltage divider potentiome-ter resistor 46.
The silicon controlled rectifier 50 functions as a sw-itch in the electric circuit of the actuator for the first sw-itch transistor 32. The control electrode or gate of the si-licon controlled rectifier functions as the actuator of the sw-itch, and it is connected across the positive and negative ter-minals 24 and 26 through a second zener diode 52. This zener diode is chosen to fire at a predetermined higher voltage th-an the zener diode 42, to establish a higher level of volt-age regulation.
As an illustration, let it be assumed that the vehicle battery 20 is a convention~ 12 volt type. Conventional single rate voltage regulators presently in use are set at the com-promise level of about 14.2 volts. As discussed hereinbefore,this level of voltage regulation provides adequate charging of a 12 volt battery, but it does so with considerable gasing and consumption of water.
For use with the exemplified 12 volt battery, the dual ra-te voltage regulator of this invention is adjusted to provide,for example, a lower level voltage regulation of about 13.2 volts, set by the zener diode 42, and a higher level voltage regulation of about 14.8 volts, set by the zener diode 52, The higher level of voltage regulation is chosen to quickly rechar-ge the battery after cranking, to replace the ampere-hours ut-ilzed during cranking. The lower level voltage regulation is chosen for continuing the recharging of the battery at a level which maintains the load demand, without any significant bat-tery gasing or water consumption. This minimizes battery ma-intenance and prevents premature plate damage, resulting insignificantly increased battery life.
It will be appreciated that the lower and higher levels of voltage regulation may be set to various values other th-an those exemplified, to accommodate a wide variety of bat-tery capacities and uses.
The operation of the dual rate voltage regulator descr-ibed hereinbefore is as follows: Let it be assumed, for il-lustration, that the DC alternator or generator is driven by the internal combustion engine of a boat, truck, passenger car, or other vehicle and that the vehicle battery is of the 12 vo-lt type and that the switch 22 represents the ignition switch of the vehicle engine.
Upon closure of the switch 22, preparatory to starting the engine through an electrical starter (not shown), the em--~" 111149t7 itter-collector switch of transistor 32 is activated to its normally "on" condition by the bias provided by resistor 36 and diode 38. Accordingly, the field coil terminal 28 is co-nnected to the positive battery terminal 24 through the nor-mally closed emitter-collector switch of transistor 32 and the diode 34.
With the engine now activated, the DC generator or alter-nator causes voltage to rise progressively as the ampere-hours used for cranking are replaced in the battery 20. Depending upon the extent of cranking, this replacement charging varies in time, for example from about 5 seconds to about a minute.
Completion of the replacement charging results in the vol-tage rising to the higher level set by the zener diode 52, ca-using the latter to fire. This completes the electric cir-cuit of the control gate of the silicon controlled rectifi-er 50, whereupon activation of the latter functions as a se-cond switch to complete the electric circuit through the zen-er diode 42 and the base-emitter of transistor 40.
Completion of the electric circuit just described, results in activation of the zener diode 42 at the lower voltage lev-el of 13.2 volts in accordance with this example. The tran-sistor 4~t~us is turned "on", whereupon the transistor 32 is turned '~9~' and the associated emitter-collector switch is - opened.
Opening of the emitter-collector switch of transistor 32 results in deenergization of the field coil of the generator or alternator 10, thereby reducing the voltage output to a level which reestablishes the blocking Osf ~te of zener diode 42. The transistor 40 thus is turned ~ , turning "on" the transistor 32 and closing its switch to reenergize the field coil.
Since the silicon controlled rectifier 50 stays latched "on" as long as DC voltage appears across the voltage divider resistances and the silicon controlled rectifier, the zener diode 42 fires intermittently as the voltage rises to the ex-exemplified lower level of 13.2 volts and then falls again.
This provides continued regulation at the lower voltage level, maintaining sufficient charging of the battery to maintain the - load demand without any siginificant battery gasing or water consumption.
When the engine is shut down ~ opening the ignition switch 22, the regulator isshut and the silicon con-trolled rectifier 50 is unlatched. The regulating cycle thenis repeated upon closure of the ignition switch and restart-ing of the engine.
In the preferred embodiment illustrated, a resistance 54 of predetermined value is connected across the silicon con-trolled rectifier 50 so that the zener diode 42 fires whenthe voltage reaches a level slightly higher than the level ofthe exemplified 14.8 volts which causes the zener diode 52 to fire. This protects against the development of excess-ively high and therefore damaging voltage at the generator or alternator 10 in the event of malfunctioning of the sili-con controlled rectifier 50.
Resistor 56 and capacitors 58 and 60 serve to smooth out the operation of the regulator, and capacitor 62 serves to prevent premature turn-on of the silicon controlled recti-fier 50.
There may be special circumstances of heavy battery usewithout simultaneous charging, as when the vehicle engine is -~ turned off, that it may be desirable to continue charging the . battery at the higher voltage levèl. For this purpose a ti-mer 64 may be associated with the second switch actuator ze-ner diode 52, either in series, or in parallel, to maintain the diode inactive for a predetermined time after the alter-nator or generator lO has been energized. A variety of ty-pes of timers may be utilized. Exemplary of one such type is the integrated circ~uit Model No. SE-555 manufactured by Signetics Corporation.
. ~
: From the foregoing it will be appreciated that the vol-tage regulator of the present invention provides a regula-ted higher voltage level which functions to recharge a batt-ery quickly, following engine cranking, to replace the am-pere-hours used for cranking, and therea$ter to reduce the voltage to a regulated lower level for continued charging of the battery at a level which maintains the load demand with-out any significant battery gasing or water consumption. Th-is mode of operation eliminates battery sulfaction which or-dinarily results from undercharging, eliminates premature plate damage which ordinarily results from battery gasing, and significantly increases battery life while simultaneo-usly minimizing the necessity of battery maintenance. Thebattery is maintained in proper charge at all times, whether it is being used in short or long run applications.
It will be apparent to those skilled in the art that va-rious changes may be made in the type of components and cir-cuit arrangement described hereinbefore, without departingfrom the spirit of this invention.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1.
A dual rate voltage regulator for a direct current alte-rnator or generator having a field coil terminal and positive and negative output terminals for connection across a battery, the regulator comprising:
a) positive, negative and field coil terminals arranged for connection to corresponding terminals of a direct curre-nt alternator or generator, b) first electrically actuated switch means for connecting said field coil terminal to one of said positive and ne-gative terminals, c) first electric switch actuator means arranged to be con-nected across said positive and negative terminals for operation at a predetermined low level output voltage from a direct current alternator or generator to open said first switch means, whereby to limit the output ch-arging voltage to said low level, d) second electrically actuated switch means arranged to re-leasably connect said first electric switch actuator me-ans across said positive and negative terminals, and e) second electric switch actuator means connected across said positive and negative terminals and operable at a predetermined higher level output voltage from the direct current alternator or generator to close said second sw-itch means and connect said first switch actuator means across said terminals, whereby to operate the first swi-tch actuator means to open said first switch means and reduce the direct current voltage output of the alterna-tor or generator from said higher level to said low lev-el.

2.
The dual rate voltage regulator of claim 1 wherein the first switch means comprises the emitter-collector of a fir-st transistor, and the first switch actuator means includes the base-emitter of the first transistor in series with the emitter-collector of a second transistor the base-emitter of which is in series with a zener diode which is activated at said low level of output voltage.
3.
The dual rate voltage regulator of claim 1 wherein the second switch means comprises a silicon controlled rectifi-er and the second switch actuator means includes the control electrode of the silicon controlled rectifier in series with a zener diode which is activated at said higher level of out-put voltage.
4.
The dual rate voltage regulator of claim 1 wherein the first switch means comprises the emitter-collector of a fi-rst transistor, the first switch actuator means includes the base-emitter of the first transistor in series with the emi-tter-collector of a second transistor the base-emitter of which is in series with a zener diode which is activated at said low level of output voltage, the second switch means comprises a silicon controlled rectifier, and the second sw-itch actuator means includes the control electrode of the silicon controlled rectifier in series with a zener diode which is activated at said higher level of output voltage.
5.
The dual rate voltage regulator of claim 4 wherein the said electric circuit includes voltage divider means for pr-edetermining the level of said low voltage output.
6.
The dual rate voltage regulator of claim 4 including re-sistance means connected across the silicon controlled rec-tifier for activating the zener diode of the first switch actuator at a level of voltage slightly higher than the le-vel of voltage which effects activation of the zener diode associated with the silicon controlled rectifier.

7.
The dual rate voltage regulator of claim 1 including ti-mer means associated with the second switch actuator means for maintaining the latter inactive for a predetermined time after energization of the alternator or generator.
CA319,788A 1979-01-17 1979-01-17 Dual rate voltage regulator Expired CA1111497A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CA319,788A CA1111497A (en) 1979-01-17 1979-01-17 Dual rate voltage regulator

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CA319,788A CA1111497A (en) 1979-01-17 1979-01-17 Dual rate voltage regulator

Publications (1)

Publication Number Publication Date
CA1111497A true CA1111497A (en) 1981-10-27

Family

ID=4113350

Family Applications (1)

Application Number Title Priority Date Filing Date
CA319,788A Expired CA1111497A (en) 1979-01-17 1979-01-17 Dual rate voltage regulator

Country Status (1)

Country Link
CA (1) CA1111497A (en)

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