I offer a homemade device allows you to control voltage vehicle electrical system. In particular, that’s all right — the battery is charged and generates the required 12-14,8 V, the signal indicator is green light. At lower voltages the light turns yellow, and when elevated — red led.
Schematic diagram of the device is quite simple, does not contain expensive or in short supply electronic components and therefore accessible even to novice hams. All fixed resistors in it — the type of MLT-0,125 or similar. As tuning elements, it is recommended to use a SPZ-196, and the role of the condenser — K50-35.
Chip К1401УД2А can be imported LM324N. Instead of the Zener diode Д818Д suitable Д814В or Д814Г.
Of even greater scope — when selecting diodes VD2—VD5. Will fit any small-size pulse analogs of silicon KD522B, designed for direct current of at least 50mA. There are plenty to choose from and the LEDs. Especially among branded, having, as a rule, the greater the brightness.
A circuit diagram and a printed circuit Board, a homemade device to control the voltage of the car
The establishment of a special instrument complexity is no different. Filing scheme the reference voltage is 11 V (for example, from a regulated power supply unit), the adjustment resistor RZ light yellow HL3. Then, gradually increasing Uконтр to 12 In the movement of the slider of resistor R2, to achieve the display of the green HL2. When this led goes out HLЗ. After that red indicator light. Increasing the trimming resistor R1 is the reference voltage to 14.8 V, light led HL1. While HL2 are out.
Capacitor C1 smooths out the ripple, and the VD5 diode protects the device against incorrect connection to voltage different than that provided by the scheme, polarity.
S. AKHMETSHIN, Ekaterinburg