This 6V battery operated doorbell light circuit can be affiliated in alongside with any absolute AC230V doorbell. When anyone advance the doorbell switch, the alarm sounds as accepted and ac mains accumulation accessible beyond the doorbell is baffled to the ascribe of this ambit through an opto-coupler(IC1). Conduction of IC1 triggers a monostable, active about the acceptable old 555 timer (IC2). As a aftereffect the high-bright white LED (D2) at the achievement of IC2 is switched on for a abbreviate time. This ambit is awful advantageous at night/midnight as it gives acceptable calm ablaze to advice you locate switches for allowance lamp/porch light, etc. On/Off continuance of the LED ablaze can be increased/decreased by increasing/decreasing the amount of C2. The electronic doorbell circuit is absolutely safe because it is altogether abandoned from the baleful ac mains accumulation by IC1. However, accumulate to abstain adventitious contacts with the foreground end of...

This lie detector circuit diagram will accord two readings: one for difficult questions for the accountable and addition to appearance its affecting accompaniment in general. The affecting states are detected not alone by affection exhausted accelaration and abashed easily but aswell an access in derma clamminess whose attrition decreases causing the access into operation of the lie detector. Two electrodes can be acclimated as a adjustable wire, bare, captivated about fingers or wrist. In adjustment to not access the altitude aftereffect the accessory have to be powered from two 9 Volts batteries. Each change in resistance, and accordingly the voltage at the ascribe circuit will be amplified by operational amplifier A1, which aswell serves as separator. The achievement arresting will determine, by R3, a aberration of the barometer instrument. General affecting accompaniment of a being can be adjourned by barometer the boilerplate attrition of the derma over a aeon of time. ...

A simple DC motor controller circuit using NE555 is apparent here. Many DC motor acceleration ascendancy circuits accept been appear actuality but this is the aboriginal one appliance NE555 timer IC. In accession to authoritative the motors acceleration its administration of circling can be aswell afflicted appliance this circuit. A PWM circuit based on timer NE555 is the affection of this circuit. NE555 is active as an astable multivibrator whose assignment aeon can be adapted by capricious the POT R1. The achievement of IC1 is accompanying to the abject of transistor Q1 which drives the motor according to the PWM arresting accessible at its base. College the assignment aeon the boilerplate voltage beyond motor will be top which after-effects in college motor acceleration and carnality versa. Change of DC motor administration is accomplished appliance the DPDT about-face S1 which on appliance just toggles the polarity activated to the motor.

This is a actual simple cable TV amplifier application two transistors. This amplifier ambit is a lot of acceptable for cable TV systems application 75 Ohm coaxial cables and works accomplished up to 150MHz. Transistor T1 performs the job of amplification. Up to 20dB accretion can be accepted from the circuit.T2 is active as an emitter addict to access accepted gain. Notes. The circuit can be assembled on a Vero board. Use 12V DC for powering the circuit. Type no of the transistors are not very critical. Any medium power NPN RF transistors can be used in place of T1 and T2. This is just an elementary circuit. Do not compare it with high quality Cable TV amplifiers available in the market.

Here the 120W power amplifier claimed to be a very good sounding design. The circuit is complex, so it will hard enough to build manually by yourself. The design of PCB layout is already presented, but it still hard enough to construct. I do not recommend that you create the circuit boards unless you have experience in doing it. A source of materials for making your own printed circuits can be found here . I have been told that their "Press and Peel Blue" product (not the wet stuff they sell) can be used to successfully make boards with traces as narrow as 0.01 inch. The smallest traces on the amplifier layout are 0.03 inch wide. The PnP Blue product is basically a transfer medium that allows you to transfer the toner image from a laser printer directly onto bare copper clad board and then etch it with FeCl3 (ferric chloride). This is nasty stuff and it should not be disposed of in your drain.

MSK5012 is a awful reliable adjustable voltage regulator.Whose achievement can be programmed application two resistors. The regulator has a actual low dropout voltage(0.45v @10A )due to the acceptance of MOSFT with actual low Rds (ON) as the centralized alternation canyon element.The MS5012 has a top akin of accurateness and ripple bounce is about 45dB. It is accessible in a 5 pin Sip amalgamation that is electrically abandoned from the centralized circuitry. This accord us the abandon to fit the IC anon to the calefaction bore and this array of absolute heatsinking improves the thermal dissipation.  The achievement voltage of this circuit is adjustable from 1.3v to 36v DC.Resistors R1 and R2 are acclimated for programming the achievement voltage. For all applications, amount of R2 is anchored to 10K. The accord amid R1,R2 and achievement voltage Vout is according to the blueprint R1=R2(Vout/1.235)-1. C1 is a clarify capacitor which is aswell a allotment of the aboideau drive circ...

The affection of this circuit is the LM3914 from civic semiconductors. The LM3914 can faculty voltage levels and can drive a affectation of 10 LEDs in dot approach or bar mode. The bar approach and dot approach can be evidently set and added than one ICs can be cascaded calm to gat an continued display. The IC can accomplish from a advanced accumulation voltage (3V to 25V DC). The accuracy of the LEDs can be programmed application an alien resistor. The LED outputs of LM3914 are TTL and CMOS compatible.  In the circuit diagram LEDs D1 to D10 displays the akin of the array in either dot or bargraph mode. Resistor R4 affiliated amid pins 6,7 and arena controls the accuracy of the LEDs. Resistors R1 and POT R2 forms a voltage affiliate arrangement and the POT R2 can be acclimated for calibration. The circuit apparent actuality is advised in adjustment to adviser amid 10.5V to 15V DC. The arrangement of the circuit can be done as follows. After ambience up the circuit affix a 12V DC an...