Archive for the ‘Power Supply’ Category
5V FET Voltage Regulator
This voltage regulator circuit gives a stable 5V output from unregulated inputs (more than 5V). The stability of the output voltage is good enough, only change less than 0.1 volts when the load current changes about 60mA. Here is the schematic diagram of the circuit: The basic principle of the voltage regulation rely on the …[Read More]
Low Power Under- and Over-Voltage Monitor
This voltage monitor has two threshold, VTH for undervoltage and VTH’ for overvoltage. Using the component values shown in the schematic diagram below, this circuit give 6V for VTH and 15V for VTH1. Above 6V, the LED indicator of this voltage monitor circuit will increase the flash rate until reach 15V. This circuit will stop …[Read More]
A battery level indicator circuit is depicted in the schematic diagram below. This circuit is designed for 9V battery operation, as this circuit will start dimming below 7V and will be completely turned off at 6V. If you want the LED indicator not to dimming but just abruptly turns off at below 6V, then you …[Read More]
10 mA, 100 mA, and 1 A Current Source
The circuit of the milliohm adapter is shown on the following figure. Under test, it can apply 1 A, 100 mA, or 10 mA to the resistance. If your voltmeter is set on the 2 V range, the current application will indicate the resistance directly in millivolts. B1 is the high current source. B1 is …[Read More]
Single-Cell Voltage Monitor
Monitoring battery voltage can be important in some application. Some battery monitor will be simply a continuous LED lamp which is dimming according to the voltage level. Here is presented monitoring circuit that flashing, which is more noticeable than simple dimming the light intensity. At 1.2V, the LED begin flashing, and the flashing rate will …[Read More]
LT1020 Battery Backup Regulator
A low-loss way to implement a”glitch-free” battery backup for a memory or similar circuit is shown on the following schematic diagram. To make LT1020 does not conduct under line-powered conditions, we have to arrange the feedback string. The line LT1020 begins to go off when the lie goes down, which allows the battery-driven LT1020 to …[Read More]
0-50V 1A Laboratory Power Supply
Laboratory power supply is characterized by its wide adjustable voltage range and its robustness. Continuous voltage adjustment is necessary, as well as current limiter for safety and robustness. You can build suitable one using LM10 op-amp and voltage source IC as shown in the schematic diagram below: The output voltage is adjustable between 0-50V, with …[Read More]
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