Devices for Measuring Voltage of a Power Supply, Detection Devices, and Temperature Controllers

Abstract

Disclosed are exemplary embodiments of devices for measuring voltage of a power supply. Also disclosed are exemplary embodiments of detection devices and temperature controllers comprising such devices for measuring voltage of a power supply. In exemplary embodiments, a device for measuring the voltage of a power supply generally includes a resistor, a capacitor, and a control unit. One end of the capacitor is connected with the resistor, while the other end of the capacitor is connected to ground. The control unit is connected with the power supply. The control unit includes a comparator connected with the capacitor, a reference power supply connected with the comparator, a timer, and a computing unit.

What is claimed is: 
     
         1 . A device comprising:
 a resistor;   a capacitor having a first end connected with the resistor and a second end connected to ground; and   a control unit connected with a power supply, the control unit including a comparator connected with the capacitor, a reference power supply connected with the comparator, a timer, and a computing unit;   wherein:
 the device is configured for measuring voltage of the power supply; 
 the timer is operable for measuring a time interval between the time when the voltage of the capacitor begins to discharge after being fully charged and the time when the voltage across the capacitor is equal to the voltage of the reference power supply; and 
 the computing unit is operable for calculating the voltage of the power supply based on the time interval, the voltage of the reference power supply, the resistance of the resistor, and the capacitance of the capacitor. 
   
     
     
         2 . The device of  claim 1 , wherein the computing unit is operable for calculating the voltage of the power supply based on the equation Ez=Vcc*EXP(−t/RC) in which Ez is the voltage of the reference power supply, Vcc is the voltage of the power supply, t is the time interval, R is the resistance of the resistor, and C is the capacitance of the capacitor. 
     
     
         3 . The device of  claim 1 , wherein the device is (a) a detection device for measuring voltage and temperature, and/or (b) a temperature controller. 
     
     
         4 . The device of  claim 3 , comprising a thermistor connected to the capacitor. 
     
     
         5 . The device of  claim 4 , wherein the control unit is operable for controlling the capacitor to discharge through the resistor or the thermistor when the capacitor is fully charged and begins to discharge, and for measuring the voltage of the power supply or the temperature of the environment ambient to the thermistor. 
     
     
         6 . The device of  claim 1 , wherein the reference power supply includes an absolute reference power supply and a relative reference power supply. 
     
     
         7 . The device of  claim 1 , wherein the comparator is selectively operable to determine temperature and voltage of the reference power supply. 
     
     
         8 . The device of  claim 1 , wherein the device is for measuring voltage of a battery power supply. 
     
     
         9 . A device comprising:
 a control unit connectible with a battery; and   a capacitor connected with a resistor and with a comparator switchable by the control unit between relative and absolute reference power supply voltages;   wherein:
 the control unit is configured to receive a first timer interrupt indicating completion of a first time interval during which the capacitor has discharged through the resistor from a fully charged state to a voltage equal to the relative reference power supply voltage; 
 the control unit is configured to receive a second timer interrupt indicating completion of a second time interval during which the capacitor has discharged from a fully charged state through the resistor to a voltage equal to the absolute reference power supply voltage; and 
 the device is operable to determine the voltage of the battery based on the first and second time intervals and the relative and absolute reference power supply voltages. 
   
     
     
         10 . The device of  claim 9 , wherein:
 the capacitor is connected with a thermistor; and   temperature of the environment ambient to the thermistor and the voltage of the battery are both determined using the comparator.   
     
     
         11 . The device of  claim 10 , wherein the capacitor is selectively dischargeable through the resistor or the thermistor, and the control unit is further configured to:
 receive a third timer interrupt indicating completion of a third time interval during which the capacitor has discharged through the resistor from a fully charged state to a voltage equal to a selected one of the reference power supply voltages; and   receive a fourth timer interrupt indicating completion of a fourth time interval during which the capacitor has discharged through the thermistor from a fully charged state to a voltage equal to the selected one of the reference power supply voltages;   wherein the device is operable to determine the temperature of the environment ambient to the thermistor, using the resistance of the resistor and the third and fourth time intervals.   
     
     
         12 . The device of  claim 10 , further operable to use the determined temperature of the environment ambient to the thermistor to determine the absolute reference power supply voltage. 
     
     
         13 . The device of  claim 10 , wherein the capacitor is chargeable by the battery selectively through the resistor or the thermistor. 
     
     
         14 . The device of  claim 10 , wherein the resistor and thermistor are each switchable to connect with ground or with the battery voltage. 
     
     
         15 . The device of  claim 9 , wherein the comparator is switchable to receive the absolute reference power supply voltage through a chip port. 
     
     
         16 . The device of  claim 9 , wherein the device is (a) a detection device for measuring voltage and temperature, and/or (b) a temperature controller. 
     
     
         17 . A device comprising:
 a control unit connectible with a battery and configured for receiving timer interrupts;   a capacitor selectively dischargeable through a resistor or through a thermistor;   a comparator connected with the capacitor and selectively configurable for prompting a timer interrupt to the control unit indicating completion of a time interval during which voltage across the capacitor has been discharged, through a selected one of the resistor and the thermistor, from a full charge to a selected one of a relative and an absolute reference power supply voltage;   the device configured to determine voltage of the battery based on:
 a first time interval during which the capacitor is discharged through the resistor from a full charge to the relative reference power supply voltage, 
 a second time interval during which the capacitor is discharged through the resistor from a full charge to the absolute reference power supply voltage, and 
 the relative and absolute reference power supply voltages; 
   the device further configured to determine temperature ambient to the thermistor, using a third time interval indicated to the control unit via the comparator, during which the capacitor is discharged through the thermistor from a full charge to a selected one of the relative and absolute reference power supply voltages.   
     
     
         18 . The device of  claim 17 , further operable to use the determined temperature of the environment ambient to the thermistor to determine the absolute reference power supply voltage. 
     
     
         19 . The device of  claim 17 , wherein the comparator is switchable to receive the absolute reference power supply voltage through a chip port. 
     
     
         20 . The device of  claim 17 , wherein the device is (a) a detection device for measuring voltage and temperature, and/or (b) a temperature controller.