In older cars, the battery charging voltage is controlled mechanically. The regulator consists of a relay that switches the stator windings of the alternator on and off. This arrangement is prone to breakdown, inaccurate regulation and sensitivity to load variations. An electronic alternative as shown has the advantages of not containing any moving parts and[…]
Read moreCategory: Voltage Regulators Circuit Diagrams
Battery charging regulator
Philips, IC Type TEA1100 uses the delta-peak principle to charge nickel-cadmium (NiCd) and nickel-metal-hydride (NiMH) batteries fast and effectively. The task of the delta-peak battery charging regulator is to ascertain and evaluate the change in the battery voltage: if the voltage at pin 7 drops 1% or more below the average maximum, charging is discontinued.[…]
Read moreRegulator output delay
In this circuit, a 317 variable voltage regulator has been provided with a facility whereby, after the input voltage has been switched on its output voltage rises only slowly to the value set with P1. For instance, if P1 was set for an output of 15 V, that value is reached only after 5 seconds.[…]
Read moreLow-drop regulator 2
Low-drop regulator 2: Nowadays the only reasons for not using a voltage regulator in a power supply are: I have not got one: I need an ‘odd’ voltage: I want to keep I the current drain very low. The regulator shown in the diagram is suitable for currents of 5-10 mA. The two transistors draw[…]
Read moreLow-drop regulator 1
Low-drop regulator 1: If a stable 5-V direct voltage is to be derived from a low supply voltage, the 4805 from SGS Thomson is probably the most suitable regulator IC available at present. The popular 7805 does not work too well with supplies lower than about 8 V. The 4805, on the other hand, needs[…]
Read moreSuper voltage regulator
A voltage regulator with properties 5 like low voltage drop, 1 A current. protected against reversal and volt-age peaks.up to 60 V, inexpensive, and simple to design it is indeed a super device. It concerns here National Semiconductor’s LM294 IC, which is an integrated device with five pins. Three pins are for the usual connections;[…]
Read morePresettable shunt regulator
Depending on their location, linear voltage regulators are arranged traditionally into two sub-groups: series and shunt (or parallel) regulators. In practical circuits, series regulators. particularly the popular integrated types in the 78xx family, are normally used since these give good regulation and allow a reasonable output current. Nevertheless, good shunt regulators are also becoming available,[…]
Read moreMicroprocessor supply regulator
Microprocessor supply regulator: Motorola’s TCA5600 is a versatile 03v supply chip for battery-operated microprocessors; its internal circuit diagram is given in Fig. 1. Diodes D1 and D2 protect the circuit against reverse polarity of the supply voltage and voltage peaks respectively. The 2.5 V reference is powered independently to enable it remaining switched on while[…]
Read more
Regulator Short Circuit Indicator Circuit Diagram
Why we need Short Circuit Indicator? Modern integrated voltage regulators are protected against short circuits but do not give an indication when a short circuit occurs. In the case of regulators with the fixed output (78xx), a short-circuit indicator is easily arranged by connecting an LED and series resistor across the regulator output. The LED[…]
Read more
Fuse monitor
When an appliance ceases to —K operate, there may be various causes for this, one of which is the blowing of the mains fuse. The monitor proposed here contains an LED that lights when that is the case. It is suitable for use with fuses rated from milliamperes to amperes. As long as the fuse[…]
Read more