My Light Diagram

Simple DCF77 Preamplifier Circuit Diagram . A popular project among microcontroller aficionados is to build a radio-controlled clock. Tiny receiver boards are available, with a pre-adjusted ferrite antenna, that receive and demodulate the DCF77 time signal broadcast from Mainf lingen in Germany. DCF77 has a range of about 1,000 miles. All the microcontroller need do is decode the signal and output the results on a display. The reception quality achieved by these ready-made boards tends to be proportional to their price. In areas of marginal reception a higher quality receiver is needed, and a small selective preamplifier stage will usually improve the situation further. The original ferrite antenna is desoldered from the receiver module and connected to the input of the preamplifier. This input consists of a source follower (T1) which has very little damping effect on the resonant circuit. A bipolar transistor (T2) provides a gain of around 5 dB. The output signal is coupled to the ant...

A difficult problem in the design of conventional stereo tone controls is obtaining synchronous travel of the potentiometers. Even a slight error in synchrony can cause phase and amplitude differences between the two channels. Moreover, linear potentiometers are often used in such controls, and these give rise to unequal performance by human hearing. Special potentiometers that counter these difficulties are normally hard to obtain in retail shops. A good alternative is a control based on a rotary switch and a discrete potential divider. The problem with this that for good tone control more than six steps are needed, and switches for this are also not readily available. Fortunately, electronic circuits can remove these difficulties.     The analogue selectors used may be driven by mechanical switches, standard logic circuit or a microcontroller. The selectors used in the present circuit are Type SSM2404 versions from Analogue Devices, which switch noiselessly. Each IC contains...

How to Build a Simple Audio Amplifier 2800W Circuit Diagram . This is a Mono high power amplifier is actually a powerful 1400 W, but if this high power amplifier circuit is doubled and you want to create stereo, high power amplifier the necessary components and pcb requires two-fold. So if the stereo high power amplifier 2 X 1400W. Schematic Circuit diagram is still less by looking at the circuit that was so below, the finished circuit has been added with a gains using JRC4558 IC by the two and the picture ic where it can be seen below.  For circuit buffers, drivers, and booster use multiple transistors and other components (can be seen listed component). And high power amplifier project that is so below is just part of the buffer and driver while the booster has not been made​​. For additional transistors in the booster or high power amplifier end scheme can be found Booster output power amplifier.  Audio Amplifier 2800W Circuit Diagram Part List : Resistor R1_____560Ω R2___...

If you want to operate power LEDS with a truly constant current which significantly prolongs the lifetime of the lamp and avoid the power loss resulting from using a constant voltage supply with a series resistor, you need a suit-able constant current source. However, the only way to achieve really good efficiency is to use a switching regulator. Altogether, this means that you need a switching regulator designed to generate a constant current instead of a constant voltage. With this in mind, the author started working on the development of a LED pocket torch with especially high efficiency. Along with using high-capacity rechargeable batteries to maximise operating life, it’s worthwhile to be able to reduce the brightness, and therefore the operating current of the LEDs, when you don’t need full power. Accordingly, the author incorporated a dimming function in the design, based on operation in PWM mode in to reduce power losses to an absolute minimum. Power LED Driver Circuit Diagram...

To day i share a little power for my friends.This is a Simple 1 Watt PLL FM Broadcast Transmitter . The RF output varies from 500mW to about 1.2W depending on the frequency selected and RF output transistor used. Motorola 2N4427 always seems to work well. Transmitter uses CMOS PLL VCO that prevents the frequency drifts. The frequency is selected via DIP switches. The transmitter is supplied by 12V DC and can also be powered from the battery.   Simple 1 Watt PLL FM Broadcast Transmitter

The alarm may be used for a variety of applications, such as frost monitor, room temperature monitor, and so on. In the quiescent state, the circuit draws a current of only a few microamperes, so that, in theory at least, a 9 V dry battery (PP3, 6AM6, MN1604, 6LR61) should last for up to ten years. Such a tiny current is not possible when ICs are used, and the circuit is therefore a discrete design. Every four seconds a measuring bridge, which actuates a Schmitt trigger, is switched on for 150 ms by a clock generator. In that period of 150 ms, the resistance of an NTC thermistor, R11, is compared with that of a fixed resistor. If the former is less than the latter, the alarm is set off. When the circuit is switched on, capacitor C1 is not charged and transistors T1–T3 are off. After switch-on, C1 is charged gradually via R1, R7, and R8, until the base voltage of T1 exceeds the threshold bias. Transistor T1 then comes on and causes T2 and T3 to conduct also. Thereupon, C1 is charged via...

This is an automatic emergency lamp with day light sensing, means it senses darkness/night and turns ON automatically. Similarly it senses day light and turns OFF automatically. A simple emergency lamp which does not require any special equipment; even a multimeter to assemble and use. Any individual who can do a good quality soldering must be able to build this circuit successfully. This can be easily accommodated in the defunct two 6 watt tube National Emergency Lamp or any PL tube type emergency lamp. The difference will be in the working; it will work non stop for more than 8 hours. Deep discharge is taken care by the LED characteristic and over charge protection is taken care by the fixed voltage regulator.This uses a simple 3Pin fixed regulator which has a built in current limiting circuit. Simple Emergency Light Circuit Diagram: The only required adjustment is the preset which has to be set to ensure the LEDs just light up (it should be left at that position). The 5mm LDR is jus...

This is a Simple Active crossover Circuit Diagram with TL074. An audio source, like a mixer, preamp, EQ, or a recorder, is fed to the input of the Electronic Crossover Circuit. This signal is either AC or coupling, depending on the setting of switch 51, the non-inverting input of buffer amplifier Ul-a, a section of a quad BIFET, low amp TL074 noise made by Texas Instruments op. This stage has a gain of 2, and its output is distributed to both a low pass filter made by R4, R5, C2, C3, and Uld op-amp, and a high-pass filter made by R6, R7, C4, C5, and op amp ULC.  These are12 dB / octave Butterworth filters. The response of the Butterworth filter was chosen because it gives the best compromise between the damping and phase. The values of capacitors and resistors varies depending on the selected connection that your device works. The filter outputs are fed to a balancing network made by R8, R9, RIO, R14 and potentiometer RLL balance. When the potentiometer is at its center position, t...

This is a project of Simple 2W Amplifier Circuit DiagramDesigned for self-powered 8, 4 & 2 Ohm loudspeakers, Bass-boost switch. This amplifier was designed to be self-contained in a small loudspeaker box. It can be feed by Walkman, Mini-Disc, iPod and CD players, computers and similar devices fitted with line or headphone output. Of course, in most cases you will have to make two boxes to obtain stereo. The circuit was deliberately designed using no ICs and in a rather old-fashioned manner in order to obtain good harmonic distortion behavior and to avoid hard to find components. The amplifier(s) can be conveniently supplied by a 12V wall plug-in adapter.Closing SW1 a bass-boost is provided but, at the same time, volume control must be increased to compensate for power loss at higher frequencies. . Simple 2W Amplifier Circuit Diagram 2W Amplifier Circuit Diagram Parts: P1----------10K R1----------33K R2----------33K R3----------33R R4----------15K R5----------1K R6----------1K R7--...

                                                    B1=AC BUZZER

This is a simple and useful circuit diagram of an FM transmitter is sown in this schematic . This FM Transmitter software is very simple and it has a acceptable transmission . The signal transited from this FM transmitter can be received at almost 300 meters in open air The circuit require a 3volts operating voltage and can be tuned anywhere in the FM band. 3V FM Transmitter Circuit Diagram You can use this emitter circuit to transmit signal from your house to garden or from room to room . To listen the signal you can use any radio (portable or not ) that can work on FM band . Connect a half or quarter wavelength antenna (length of wire) to the aerial point. At an FM frequency of 100 MHz these lengths are 150 cm and 75 cm respectively. The calibration of this FM emitter circuit is very simple and you need just to place a radio at some distance from the transmitter and set it somewhere about 88-107MHZ( chose the transmission frequency ) and after that vary the transmitter oscillator fre...

A remote listening circuit. The area to be monitored is connected via a cable and allows remote audio listening. Simple Security Monitor Circuit Diagram: Notes: You can use this in your garden and listen for any unusual sounds, or maybe just wildlife noises. If you have a car parked in a remote location, the microphone will also pick up any sounds od activity in this area. The cable may be visible or hidden, screened cable is not necessary and you can use bellwire or speaker cable if desired. Circuit Description: Starting from the right hand side, the power supply. I have used 12V as a standard power supply voltage, or a 12V car battery may be used. The circuit is in two halves, a remote microphone preamp, and an audio amplifier based around the National Semiconductor LM386 audio amplifier. The remote preamp uses an ECM microphone to monitor sound. A direct coupled 2 stage amplifier built around Q1 and Q2 amplify the weak microphone signal. Preset resistor R2 acts as a gain control, an...

Simple FM stereo decoder circuit using MC1310P IC via next.gr

This is the Simple 140W amateur radio linear amplifier 2-30Mhz Circuit Diagram. This inexpensive, easy to construct amplifier uses two MRF454 devices. Specified at 80 W power output with 5 W of input drive, 30 MHz, ana 12 Vdc. Simple 140W amateur radio linear amplifier 2-30Mhz Circuit Diagram

The above pictured schematic diagram is just a standard constant current model with a added current limiter, consisting of Q1, R1, and R4. The moment too much current is flowing biases Q1 and drops the output voltage. The output voltage is: 1.2 x (P1+R2+R3)/R3 volt. Current limiting kicks in when the current is about 0.6/R1 amp. For a 6-volt battery which requires fast-charging, the charge voltage is 3 x 2.45 = 7.35 V. (3 cells at 2.45v per cell). So the total value for R2 + P1 is then about 585 ohm. For a 12 V battery the value for R2 + P1 is then about 1290 ohm.  For this power supply to work efficiently, the input voltage has to be a minimum of 3V higher than the output voltage. P1 is a standard trimmer potentiometer of sufficient watt for your application. The LM317 must be cooled on a sufficient (large) coolrib. Q1 (BC140) can be replaced with a NTE128 or the older ECG128 (same company). Except as a charger , this circuit can also be used as a regular power supply . Parts ...

This 30v variable power supply circuit is based on LM317   voltage regulator circuit . This LM317 30v variable power supply circuit can deliver high current (around 5 amps) and variable output voltage between 1.2 volts, up to 30 volts. The led D3 mounted on pin 6 at lm301 lights in constant current mode . Circuit diagram  Current limit can be adjusted using R2 potentiometer and the output voltage can be adjusted from 1.2 volts to 30 volts using R8 potentiometer . Input voltage for this variable power supply must be around 35 volts .For this power supply circuit you need to use LM317K circuit (in to3 package ) which must be mounted on a heatsink .

Simple Dual Trace Scope Switch Circuit Diagram. The switcher output goes to the single vertical input of the scope, and a sync line from one of the inputs is taken to the scope's external-sync input. Frequency response of the input amplifiers is 300 kHz over the range of the gain controls. With the gain controls wide open so no attenuation of the signal takes place, the frequency response is up to 1 MHz. Simple Dual Trace Scope Switch Circuit Diagram    

Circuit of an automatic switch for audio power amplifier stage is presented here. The circuit uses stereo preamplifier output to detect the presence of audio to switch the audio power amplifier on only when audio is present. The circuit thus helps curtail power wastage. IC1 is used as an inverting adder. The input signals from left and right channels are combined to form a common signal for IC2, which is used as an open loop comparator. IC3 (NE556) is a dual timer. Its second section, i.e., IC3(b), is configured as monostable multivibrator. Output of IC3(b) is used to switch the power amplifier on or off through a Darlington pair formed by transistors T1 and T2. IC3(a) is used to trigger the monostable multivibrator whenever an input signal is sensed. Circuit diagram: Automatic Switch For Audio Power Amplifier Circuit Diagram Under ‘no signal’ condition, pin 3 of IC2 is negative with respect to its pin 2. Hence the output of IC2 is low and as a result output of IC3(a) is high....

This is the Simple Low Distortion Audio Amplifier Circuit Diagram. The circuit was designed and sold as a card by a purveyor of surplus components but, even using mostly manufacturer's rejected transistors, we managed to get about 0.02% total harmonic distortion at 30 watts with a ±25v power supply into 8 ohms.: no bad figure even in these days of MOSFET and ICs. In 1977 anything below 0.1% was considered excellent. And this figure was pretty repeatable without doing much selection.  The problem of course is that since I haven't touched this amplifier for many a year I have absolutely no idea what modern transistor types one should use for it but they are not critical: output transistors and drivers need to be the correct type but the other transistors can be small signal types - as long as they can handle the full voltage between + and - supplies.  Simple Low Distortion Audio Amplifier Circuit Diagram   Tr1 and Tr2 are a long-tailed pair (LTP to save typing). It is quite...

Simple 3 volt to 9 volt with LMC555 Circuit Diagram . This is a Build a 3 volt to 9 volt with LMC555 Circuit Diagram. This dc converter is built with the CMOS version of 555 timer. You can get 12V too if you change the zener diode to a 12V version. 3 volt to 9 volt with LMC555 Circuit Diagram