The DS1669 is an electronic digital rheostat manufactured by Dallas Semiconductor. This component has a function similar to digital variable resistor/potensiometer which can be operated by push the buttons. You can adjust the audio volume, LCD contrast, frequency, etc. by using two buttons instead of a common potentiometer/trimpot. This circuit explains how we do it… Read More »
Here the variable desktop power supply which will convert a high input voltage (12V) from the SMPS / PSU of a desktop computer into small output voltage (1.25 to 9 volts). This converter will be very beneficial for electronics hobbyists. An adjustable three-pin voltage regulator chip LM317T (IC1) is applied right here to deliver the… Read More »
A well-known IC LM35 is chosen to be the temperature sensor in this circuit. Output voltage of LM35 will increase by 10mV per degree rise in temperature. Output of LM35 is joined to the non inverting input of the operational amplifier (op-amp) of CA3130. The inverting input of the same op-amp could be provided using the required reference voltage using variable resistor R2.
This is the circuit connection of home telephone call recorder that uses very few components. In order to understand its working, we must first have the basic knowledge of standard telephone wiring and a stereo plug. In some countries, landline telephones primarily use RJ11 wiring, which has two wires—tip and ring. While tip is the… Read More »
This battery charger circuit is regulated and adjustable to make this circuit able to charge the mosto NiCAD battery. This adjustable regulated battery charger circuit will work for single cell or multi battery cell which connected with series/parallel connection. The maximum voltage of the batteries should be 18V maximum. Power transistors Q1 and Q2 are… Read More »
This is the electronic circuit diagram of aquarium temperature probe capable to monitor the temperature of water and indicate the rise in temperature through audio-visual indicators. This circuit uses diode 1N34 as the temperature sensing probe. The resistance of the diode will be vary depends on the temperature in its vicinity.
This is the circuit diagram of 230V automatic night lamp based photo resistor to sensing the light environment. When the condition is dark enough, the one or more lamps will be turned on and when the condition is bright enough, then the lamps will be turned off.
This is the circuit diagram of battery charger which has many important features such as current-constant charging, overcharge protection, short-circuit protection, deep discharge protection and more. The constant-current charging is a popular method for lead-acid and Ni-Cd batteries. In this circuit, the battery is charged with a constant current that is generally one-tenth (1/10) of… Read More »
Here is the circuit diagram of stereo digital volume control. This circuit could possibly be applied for upgrading your manual volume management within a stereo amplifier circuit. In this particular circuit, push-to-on switch S1 controls the forward (volume enhance) operation of the two channels while a identical switch S2 controls reverse (volume reduce) operation of… Read More »