12V Stroboscope 250-400V DC Circuit

The stoboscope tube needs about 250-400V DC to operate. This high voltage is generated using simple voltage step up circuit built from transistors Q1,Q2 and transformer T1. This circuit gives out about 230V AC voltage which is then rectified with rectifying bridge U1 (must have at least 400V voltage rating) and stored to the main capacitor C1. I built my stroboscope from parts taken from old camera flash unit. This approach gave me nice flash tube with reflector, trigger transformer and some of the capacitors (for example C1). Other parts were the one luying around. I used some strange triac I found in my for the triggering circuit,...

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Output Relay Delay Audio Amplifier Circuit

Output Relay Delay Audio Amplifier Circuit This is a simple circuit which I built to one of my audio amplifier projects to control the speaker output relay. The purpose of this circuit is to control the relay which turns on the speaker output relay in the audio amplifier. The idea of the circuit is wait around 5 seconds ofter the power up until the spakers are switched to the amplfier output to avoid annoying “thump” sound from the speakers. Another feeature of this circuit is that is disconnects the speaker immdiatly when the power in the amplifier is cut off, so avoinding sometimes nasty sounds when you turn the equipments off. Output...

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10.58 to 10.74 MHz VFO Oscillator Circuit

Figure 1, below, shows the 10.58 to 10.74 MHz VFO oscillator circuit. Yes, this is the same circuit that was presented last time, but I’ve re-drawn it to show the Colpitts oscillator more clearly. “L” is approximately 1.5 uH; 19 turns in a T50-6 core (yellow). The value of C6 is found experimentally. I used 69 pF (a 47 pF and a 22 pF in parallel). More about this during check-out. 10.58 to 10.74 MHz VFO Oscillator Circuit “L” and the V V C along with C6 make up the parallel-tuned circuit that determines the frequency of the VFO. The V V C is an MV2104. Capacitors marked with an asterisk must be silvered mica, COG, or NPO. You might...

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RS-232 Reset for Microprocessor

RS-232 Reset for Microprocessor Introduction This circuit allows a remote microprocessor to be reset by a controlling host by sending a break signal over an RS-232 or RS-422 serial line. If the remote machine resets into a simple program loader program, it is possible for the host to halt and restart, or halt and reload/restart the remote machine’s program. This is an ideal way to develop software on older EPROM-based systems. Modern EEPROM/NVRAM systems use JTAG interfaces for similar results.The remote processor runs its target code out of RAM, allowing the code to be updated easily. The circuit is usually used for developing code...

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Isolated RS422 Interface Circuit and Layout

 Isolated RS422 Interface Circuit Figure 1 shows the circuit diagram of RS422 interface. Connector K1 is linked to the serial port of the PC, power to the PC side of the circuit is derived from the signal lines DTR and RTS. Positive supply is derived from RTS and negative supply from the DTR line. Optical isolation is achieved by optocouplers U1 and U2. Optocoupler  U1 provide TXD line isolation while optocoupler U2 provide RXD line isolation. The other side of the isolator carries TTL levels. This side is powered by an unregulated dc supply between 9V and 12V ac/dc adapter. IC U5 provide 5V regulated output and ICs U3 &...

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0-1000 Volt Regulated High Voltage Power Supply IC 7805

1000 Volt DC to DC Regulator Circuit Input voltage from high voltage DC DC converter is 12V AC at 800mA current and then converted to DC through a bridge rectifier Diode 1A. The voltage output of converter circuit can be adjusted in the range of 0-1000V DC. This high voltage DC DC converter uses the transformer as a base and several other active components include 555 timer IC, CMOS IC 4001, IC voltage regulator 7805, some NPN transistors and a pair of logic MOSFET IRF510 as a final amplifier.The workings of high voltage DC to DC converter is the same principle as written in previous articles. The difference shown is this converter...

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AC to DC 90 Watt Switching Power Adaptor

AC to DC 90 Watt Switching Power Adaptor Circuit AC to DC switching power adaptor circuit with maximum output power of 90W. Switching power supply is built using a high voltage power switching regulator IC MC33374 and some other additional components. The MC33374 IC is a monolithic high voltage power switching regulators that are specially designed to operate directly from a rectified AC line source, and in flyback converter applications.The MC33374 switching power adaptor combines the required converter functions with a unique programmable state controller. At various variable AC inputs, it is capable of serving up to 6 A current...

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12V DC Motor Wind Turbine

12 volt Wind Turbine It is possible to use a 12V DC motor (I assume its a car starter motor) as a wind turbine generator to provide energy conversion between the mechanical torque from the wind rotor turbines, (called the prime mover) and the connected 150V load. A gearless two or three bladed upwind wind turbine using a permanent magnet DC motor can be used to charge a battery for energy storage through a rectifier and a typical wind turbine configuration is given as: Generator Configuration However, using a low voltage DC motor as a wind turbine generator is not always a good idea for the following reasons.The DC motor may not...

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Broadband Random Noise Generator

Broadband Random Noise Generator Circuit This circuit is normally necessary in testing any sort of electronic methods for example filter, audio, or RF communication. The circuit introduced right here generates an RMS amplitude regulated noise source with selectable bandwidth. This circuit is work depending on op amp. This will be the figure with the circuit. Look at the schematic of Broadband Random Noise Generator Circuit above. With 1 KHz to 5 MHz ten years ranges selectable bandwidth and 300mV RMS output, this noise generator is suitable for wide range of software. Noise is created by D1 that is AC coupled to A2, an amplifier with...

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Two Speed Contactor DC Motor Controller Circuit

The simplest of all motor controllers (besides a straight on/off switch) is the contactor controller. I designed this contactor controller for use in my electric scooter project. It is based around three 12V relays, two 12V batteries, two switches and of course a motor. Having no silicon to “fry”, it is quite reliable and robust. A contactor controller works by rearranging the two (or more) supply batteries between series and parallel. This gives the motor a slow speed (batteries in parallel, current adds) and a fast speed (batteries in series, voltage adds). This assures that both batteries are discharged equally. When the circuit...

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Counter Wall 7 Segment Circuit Diagram

This simple counter can be used to count pulses, as the basis for a customer counter (like you see at the doors of some stores), or for anything else that may be counted. The circuit accepts any TTL compatible logic signal, and can be expanded easily (see Notes). Notes 1. All pulses to be counted are to be TTL compatible. They should not exeed 5V and not fall below ground. 2. You can add more digits by building a second (or third, or fourth, etc…) circuit and connecting the pin 11-6 junction of the 74LS90 and 74LS47 to pin 14 of the 74LS90 in the other circuit. You can keep expanding this way to as many digits as you want. Part Total...

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Stepper Motor Pulse Generator with 555

The 555 Stepper Motor Pulse Generator kit will support you together with the pulse needed to drive your favorite DC Servo Motor application. This kit uses the well-known 555 timer IC for creating the Stepping Pulse. Quick Overview # Input : 5 to 12 VDC @ 25 mA # TTL/CMOS interfaceable # Jumper selectable two speed operation # Onboard preset to vary the frequency # Power-On LED indicator # Terminal pins for easy interfacing of the kit # Four mounting holes of 3.2 mm each # PCB dimensions 39 mm x 37...

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Lightning Detector Circuit

This Do-it-yourself lightning detector circuit can be a especially sensitive static electricity detector which can supply an early warning of approaching storms from inter-cloud discharge properly prior to an earth-to-sky return strike takes location. An aerial (antenna) formed of the brief duration of wire detects storms inside a two mile radius. The circuit emits an audible warning tone from a piezo buzzer, or flashes an LED for each discharge detected, providing you advance warning of impendig storms so that precautions may be observed.The primary characteristic inside the lighting detector is the circuit’s ability to be set near...

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CD4001 Simple Alarm Circuit For Motorcycle

Simple Alarm for motorcycle with a CD4001This is a simple alarm circuit for a check with a 4001. You can use it to protect our home, motorcycle, car or any other application that comes to mind. In this circuit you will make a computer simulation with Livewire and then design the printed circuit Kicad.OPERATION SW1 is a normally closed switch when pressed triggers the flip-flop formed by the two NOR gates of the CD4001 and remains in that state for a time determined by the time constant of R5-C2. This time is the one who keeps the relay RL1 and operated by its two contacts that we investors will control two loads, for example a siren...

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Phase Delay Network for 3D Audio Enhancement

3D enhancement is needed to create a fully 3-dimensional sound for most stereo multimedia products. Usually, simple phase-delay circuits is used to produce a widening effect on the perceived sound field. However, there is transaural acoustic crosstalk effect. The following figure shows transaural acoustic crosstalk effect and schematic diagram of simple phase-delay circuits ...

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