A multiple-voltage output battery case with protection and alarm systems is provided. The present system relates generally to battery cases which hold batteries connected in a manner which allows more than one output voltage. The present system insures that the batteries will be protected from excessive current draw and further provides indication if the current is exceeded. The indication of excessive current may be audible, visual, or both. The present system may also allow for protection and warnings if some of the batteries are removed.
Voltage output protection and alarm systems of batteries have been invented in the past. For example, U.S. Pat. No. 4,255,698 to Simon discloses methods of battery charge and/or discharge control which makes use of an electrical device which is connected in series with the cell or cells of the battery and which is preferably a permanent part of the battery, so that when the battery terminals are connected in order to charge or discharge the battery, the device provides an automatic guard against excessive battery temperatures and/or current discharges. The device comprises a PTC element which is preferably composed of a conductive polymer composition, and which is in a low resistance state under normal operating conditions but which changes to a high resistance state (and thus reduces the charging current or the discharge current) when the temperature and/or current become excessive.
Further, U.S. Pat. No. 8,237,409 to Jang discloses a protective circuit module of a secondary battery and a secondary battery using the same, the protection circuit module including a positive temperature coefficient (PTC) device and a circuit board, wherein terminals of the PTC device are inserted into the circuit board to be coupled with connection terminals of the circuit board so that workability is improved and manufacturing costs are reduced. The secondary battery sensitively reacts to a temperature increase of the secondary battery by installing the PTC device on the upper or lower side of the circuit board, or extending one terminal of the PTC device to a bare cell of the secondary battery.
There are many devices and products that are powered by batteries. Many battery cells may have voltage levels from 0.8 volts when weak and over 3 volts when new. In some cases, the battery holder may be used in different circuits for educational purposes, in toys, small appliances, in industry, or in laboratories doing research to name just a few. A switch may allow the user to change the voltage but does not allow all the voltages to be available to the user simultaneously. If a connection allows too much current to flow from a battery, it may become extremely hot and the battery may even explode. The most popular voltages used today are 3, 6, 9, and 12 volts.
If each output of the battery holder is simply fused it would be cumbersome and expensive when correcting blown fuses since there could be many possible fuses. Mechanically resettable fuses are expensive and some can be overridden by holding the reset button. They also often require the added action of finding the open fuse and resetting it. These problems are resolved by using fusing circuits which limit the maximum current, indicates the troubling area, and automatically resets when normal conditions are restored. The present system may be as complicated as an integrated circuit or as simple as a positive temperature coefficient (PTC) resettable fuse which triggers an electronic beeper. Each battery with an output may require a fuse and indicator to insure full protection. One such solution is to place a PTC fuse circuit in series with each output that will limit all currents from that output to a safe level. As the current at the output increases the temperature of the PTC increases, lowers the output current and triggers an indicator for that output failure.
This reduction in current lowers the voltage out and prevents damage to both external components and the internally installed battery. As soon as the electrical current is restored to a safe level the fusing circuit will reset, restoring the output to the proper voltage. When any fusing circuit is activated it would be desirable to produce a visual and/or audible output to the user.
Table 1 Illustrates typical data for a battery holder 527 with electronic circuit 700 using 1.5 volt alkaline cells 701-704, 713 with 1 to 4 batteries installed.
Table 2 Illustrates voltages required to activate different colored LEDs.
A multiple-voltage output battery case with protection and alarm systems is provided. The present system relates generally to battery cases which hold batteries connected in a manner which allows more than one output voltage. The present system insures that the batteries will be protected from excessive current draw and further provides indication if the current is exceeded. The indication of excessive current may be audible, visual, or both. The present system may also allow for protection and warnings if some of the batteries are removed.
The present system utilizes, for example, an improved battery holder 127 with multiple voltage outputs 128-132, Positive Temperature Coefficient (PTC) fuses 115, 118, 121, 124, an audible alarm 110, a printed circuit board 135 containing electronic components 111-124 and common copper paths 125,126. In an embodiment, the fuses 115 are automatically resettable. Although the battery holder 127 and voltage outputs 128-132 may be physically designed for general use, the battery holder 127 and voltage outputs 128-132 may be modified in an embodiment for a specific purpose without changing the uniqueness or function of the present system. In the assembled battery holder 127 shown in
Referring now to
The negative end of battery 101 may be connected to a surface mount printed circuit board 135 by conductive battery tab 109. The conductive battery tab 109 may also connected to a zero volt or ground run 126 on the surface mount printed circuit board 135. The zero volt output tab 132 may also be connected to the zero volt or ground run 126 on the surface mount printed circuit board 135. The positive end of battery 101 may be connected to the surface mount printed circuit board 135 by conductive battery tab 108. Outlined section 150 illustrates that one end of a PTC fuse 124 may be connected to conductive battery tab 108 and the other end of the PTC fuse 124 may be connected to conductive output tab 131. As a result, this places the protective PTC fuse 124 in series with the positive voltage of the first battery 101 and the output tab 131 for that voltage. Any current drawn from output tab 131 which exceeds a predetermined trigger threshold for PTC fuse 124 will increase the resistance of PTC fuse 124, dropping the voltage present at output tab 131 and limiting the current from battery 101 to a safe value. Also shown in outlined fusible circuit section 150 is the emitter of a PNP transistor 122 is connected to the battery tab 108 and the base of the PNP transistor 122 is connected to one end of a resistor 123. The other end of resistor 123 may be connected to the conductive output tab 131. As a result, this may place the emitter-base of PNP transistor 122 and resistor 123 series combination in parallel with the PTC fuse 124. During normal currents through PTC fuse 124 the voltage drop across PTC fuse 124 will be too low to turn on PNP transistor 122. When the voltage drop across PTC fuse 124 rises to lower the output current at output tab 131 the PNP transistor 122 will switch on and current will flow from the collector of the PNP transistor 122 through the resistors 134 and 112 to the zero volt or ground run 126 on the surface mount printed circuit board 135.
The other three protection fusible circuits 151-153 may perform substantially similar to protection circuit 150 for batteries 102-104 respectively. The only difference may be that the negative end of battery 102 may be connected to the positive end of battery 101 and battery tab 108. The positive end of battery 102 may be connected to the surface mount printed circuit board 135 by conductive battery tab 107. Circuit section 151 performs substantially identical to circuit section 150 with output tab 130 being protected by PTC fuse 121 and voltage at output tab 130 being raised by two battery levels above zero volt or ground tab 132. The negative end of battery 103 may be connected to the positive end of battery 102 and battery tab 107. The positive end of battery 103 may be connected to the surface mount printed circuit board 135 by conductive battery tab 106.
Fusible circuit section 152 may perform substantially similar to fusible circuit section 151 with output tab 129 being protected by PTC fuse 118 and voltage at output tab 129 being raised by one battery level above output tab 130 and three battery levels above zero volt or ground tab 132. The negative end of battery 104 may be connected to the positive end of battery 103 and battery tab 106. The positive end of battery 104 may be connected to the surface mount printed circuit board 135 by conductive battery tab 105. Fusible circuit section 153 may perform substantially similar to circuit section 152 with output tab 128 being protected by PTC fuse 115 and voltage at output tab 128 being raised by one battery level above output tab 129 and four battery levels above zero volt or ground tab 132. Since the collectors of all of the PNP transistors 122, 119, 116, 113 are tied together current will flow from the collector of the PNP transistor 122, 119, 116, 113 through the current path 125 and through resistors 134 and 112 to the zero volt or ground run 126 on the surface mount printed circuit board 135.
When no current flows from any PNP transistor 122, 119, 116, 113 collector the resistor 112 keeps the base of NPN transistor 111 at zero volts and NPN transistor 111 may therein be switched off. By making the resistance value of resistor 134 small compared to the resistance value of resistor 112, when current flows from any PNP transistor 122, 119, 116, 113 collector the voltage drop across resistor 112 will rise rapidly and turn on NPN transistor 111 activating audible device 110. In this manner any excessive current drawn from output tabs 128-131 may produce an audible warning tone. The audible device 110, 712 may be replaced with a visual device such as a red light or both audible and visual warning indicators could be used simultaneously as shown in
Table 1 is provided to show data from a battery holder 527 shown in
Another instance of a battery holder 527 designed solely for cells with a 3 volt output, such as lithium batteries, is shown in
Still another instance of a battery holder 527 that uses internal circuit shown in electronic schematic 700 in
The resistor 710 needs to be valued low enough to allow sufficient current to flow to the negative supply 713 to light the LED 751-754 and high enough to produce a voltage drop that will turn on the NPN transistor 711 and activate the audio device 712. A value of 500 ohms was used for resistor 710 in the test circuit for data taken in Table 1. The resistor 709 must be low enough to allow sufficient base current into the NPN transistor 711 and high enough to limit current to the negative source 713. A value of 1000 ohms was used for resistor 709 in the test circuit for data taken in Table 1. If battery 704 is removed from the holder, output 728 will drop to zero volts and basically be an open circuit with no affect if shorted to any other output 729-732. All other outputs 729-731 will perform normally with power for the audio device 712 supplied through diode 706 from battery 703.
Audio level from audio device 712 will drop slightly due to lower voltage source. If batteries 704 and 703 are removed from the holder, outputs 728 and 729 will drop to zero volts and basically be open circuits with no affect if shorted to any other output 730-732. All other outputs 730-731 will perform normally with power for the audio device 712 supplied through diode 707 from battery 702. Audio level from audio device 712 will drop again due to lower voltage source. If batteries 704, 703, and 702 are removed from the holder, outputs 728, 729, and 730 will drop to zero volts and basically be open circuits with no affect if shorted to the last output 731 or ground 732. The remaining output 731 will perform normally with power for the audio device 712 supplied through diode 708 from battery 701. Audio level from audio device 712 will be weak due to low voltage source.
Although the inventions described by reference to this preferred embodiment could be modified by using circuits to generate a negative supply or modify other fusible circuits, it is not intended that the novel assembly be limited thereby, but that modifications thereof are intended to be included as falling within the broad scope and spirit of the foregoing disclosure, and the appended drawings.
The following application is based on and claims the priority benefit of U.S. provisional application Ser. No.: 62/328,692 filed Apr. 28, 2016 currently co-pending; the entire contents of which are incorporated by reference.
Number | Date | Country | |
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62328692 | Apr 2016 | US |