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The recent tsunami in Japan and the on-going calamity with the Fukushima nuclear power plant has apparently greatly increased sales of radiation meters, not only in Japan but elsewhere around the world. This device will allow an estimation of the level of radioactivity, being sensitive enough for background radiation monitoring or to provide an estimation of the level of radioactivity from sample objects such as Thorium gas mantles in LPG lamps. The circuit is compatible with several Geiger Muller tubes and three types of indication are provided: the good old-fashioned audible click with each discharge, a flashing LED or an analog meter providing a rough average of radiation levels. Geiger Counter Uses Cockroft-Walton Multiplier Circuit A normal background count in New Zealand with the smaller GM LND712 tube is around 30 counts per minute, while the larger and more-sensitive LND7312 pancake tube will count about four times this figure. Both GM tubes will detect alpha, beta and gamma ra

Components Required: 1) Breadboard 2) 1N4007 Diode 3) 470 ohm resistor 4) 15 Kilo ohm Light Dependent Resistor (LDR) 5) LED (Any Color) 6) 9Volt Battery 7) Digital Multimeter  Procedure: Connect the 1N4007 diode and 470 Ω resistor to one terminal of 15 Kilo ohm Light Dependent Resistor (LDR) in series. Connect the other terminal of LDR to the LED in series in a breadboard.  Connect the 9V battery's positive end to the anode of 1N4007 diode and negative end to the cathode of the LED as shown in the circuit diagram below. Measure the voltage across various points by altering the Light input on the LDR using a digital multimeter and note the change in brightness of the LED accordingly. Observe the change in LED brightness in a dark room and in a bright light. Here I have used a cap to cover the surface of the LDR to observe the change in LED brightness. Also observe the change in resistance value of the LDR using a digital multimeter which is the cause for the alteration in LED brig

Audio graphic equalizers are very common as commercial products (for Hi-fi, car audio and stage use) but circuits for them are very rarely published. I didn't design this one but it's really very simple. The details shown are for a 7 band but the principle can be extended to almost any number of bands - if you can find accurate enough components.  Only one gyrator stage is shown: all 7 gyrators are the same circuit, only the capacitors change, as shown in the chart. I have shown three of the seven faders to show where they go.  A gyrator is a circuit using active devices and transistors to simulate an inductor. In this case the gyrator is the transistor acting with R1, R3 and C2. It could just as easily be a unity gain op-amp.  The circuit includes three formulae: one which gives f, the the centre frequency of the band. The second shows how the Q is related to the capacitor ratio. The third shows the impedance presented by the circuit. Note that this includes 3 terms, the firs

If you are in the market for a surround sound system I'm sure you are trying to learn as much as possible about options before you reach the buying stage. One thing to keep in mind is that there are many options and most of them will come down to a matter of taste when all is said and done. There is no right or wrong component or process when it comes to buying a surround sound system only what does and doesn't work for you and the space you have available. You will find throughout the process that there are many parts, pieces, and components that you may purchase for your surround sound system and even more prices for those individual items. Ultimately the decision comes down to how much of a sound snob you are. Seriously. I must admit that my personal preference is for the most possible sound saturation and the most realistic possible sound as possible. For this reason I am more interested in buying the components as individuals rather than a simple AV receiver. This does no

This is a simple Cell Phone Jammer RF Amplifier Circuit Diagram. This cellular Phone Jammer RF Amplifier Circuit Diagram see below circuit and make it. Cell Phone Jammer RF Amplifier Circuit Diagram

This is a series of amplifiers are based on the most high-ic power that I have ever known. Because the output is issued up to 1000 watts with the impedance RL 4Ohm. Current supply 120mA, and 30A output current. Minimum input voltage of about 30V and a maximum voltage up to 150V. This is an audio amplifier that I have come across use ICs that maximum voltage up to 150V and output power up to 1000W , the scheme below gan. Part List Resistor R1 = 10K R2 = 10K R3 = 220K R4 = 0.18R 5W R5 = 2.2R 2W R6 = 0.18R 5W Capacitor C1 = 1uF C2 = 1000uF C3 = 68pF C4 = 1000uF Inductor L1 = 4MH IC U1 = PA03

This is a simple Electronic Router UPS Circuit Diagram Project. It can be handy to have your phone and Internet router continue working for a while after  a power failure for example, if they provide  access to a security system. This requires a  backup power supply for the router. The version described here consists of a 12-V lead-acid battery and a voltage converter capable  of supplying an output voltage in the range of  15 to 30 V. It has built-in protection to prevent  excessive battery discharge.  This is uninterruptible power supply (UPS)  operates in standby mode as long as the  mains voltage is present.  Router UPS Circuit Diagram The UPS consists of four parts: a backup  detector circuit that monitors the supply  voltage from the AC mains adapter, a battery  circuit that monitors the battery voltage to  prevent it from dropping below 11.8 V, a FET  switch between the battery and the voltage  converter, and a voltage doubler (inside the  dashed outline). To understand how it

If you’re into electronics, engineering and making things move, you’ll need a good handle on electric actuators. Use this beginner’s guide to electric actuators before you set out to purchase your first actuator. What is An Actuator? Before linear electric actuators were around, the only way to make a robot move forward was to use rotary actuators. Linear actuators changed all that. When it comes to electric actuators, you’ve got two main choices: lead screw and ball screw. You’ve really got a ton of choices, like peizo-electric, and there are a ton of innovations happening right now, but for this article, we’ll stick to the basics. Lead Screw Actuators Lead screw actuators use a threaded lead screw and a nut to create motion. The gear system runs, turning the screw moving it along the nut. Here’s a quick diagram to illustrate the idea. Ball Screw Actuators They essentially use the same principle with a lead screw and a motor, but instead of using a nut, they use small bearings that ru

This simple circuit can be used to program the PIC16F84 and similar "flash memory" type parts. It uses a cheap 555 timer IC to generate the programming voltage from a +5V rail, allowing the circuit to be powered from a computer’s USB port. The 555 timer (IC1) is configured as a free-running oscillator, with a frequency of about 6.5kHz. The output of the timer drives four 100nF capacitors and 1N4148 diodes wir-ed in a Cockroft-Walton voltage multiplier configuration. USB-Powered PIC Programmer Circuit Diagram The output of the multiplier is switched through to the MCLR/Vpp pin of the PIC during programming via a 4N28 optocoupler. Diodes ZD1 and D5 between the MCLR/Vpp pin and ground clamp the output of the multiplier to about 13.6V, ensuring that the maximum input voltage (Vihh) of the PIC is not exceeded. A 100kΩ resistor pulls the pin down to a valid logic low level (Vil) when the optocoupler is not conducting. The circuit is compatible with the popular "JDM" progr

A Simple Sound Effects Generator Circuit uses a UM3561 IC to produce four different sound effects. Circuit diagram : Simple Sound Effects Generator Circuit Diagram Notes: Nothing too complicated here. The IC produces all the sound effects, the output at Pin 3 being amplified by the transistor. A 64 ohm loudspeaker can be substituted in place of the 56 ohm resistor and 8 ohm loudspeaker. The 2 pole 4 way switch controls the sound effects. Position 1 (as drawn) being a Police siren, position 2 is a fire engine sound, 3 is an ambulance and position 4 is a machine gun effect. The IC is manufactured by UMC and was available from Maplin electronics code UJ45Y. At the time of writing this has now been discontinued, but they have have limited stocks available.

This is a schematic of a 10W stereo audio amplifier using TDA2009A amplifier IC. TDA2009A is a good IC provides quality sound. It has built in features like output current protection and thermal protection etc. The circuit can be operate between 8 to 24V DC with 1 to 2 amphere. 10W Stereo Audio Amplifier Circuit Diagram : If you want to operate this 10 watt amplifier circuit with watt amplifier circuit with mains supply then use a filtered and stable power supply to reduce mains hum. 10 watt out put power can be obtained by providing 20V 1.5A to the circuit. Use good and thick heatsink with the IC. 

Ultra-low current drawing 1.5V battery supply This circuit is usable as a Night Lamp when a wall mains socket is not available to plug-in an ever running small neon lamp device. In order to ensure minimum battery consumption, one 1.5V cell is used, and a simple voltage doubler drives a pulsating ultra-bright LED: current drawing is less than 500µA. An optional Photo resistor will switch-off the circuit in daylight or when room lamps illuminate, allowing further current economy. This device will run for about 3 months continuously on an ordinary AA sized cell or for around 6 months on an alkaline type cell but, adding the Photo resistor circuitry, running time will be doubled or, very likely, triplicated. Circuit diagram :   Battery-powered Night Lamp Circuit diagram Parts: R1,R2___________1M 1/4W Resistors R3_____________47K 1/4W Resistor (optional: see Notes) R4____________Photo resistor (any type, optional: see Notes) C1____________100nF 63V Polyester Capacitor C2____________220µF 25

Overview The STK400-030 is a 3-channel AF power amplifier IC supporting multichannel speakers. One package includes 20W×3ch for Lch, Rch and Cch. It is pin compatible with both 3-channel output devices (STK400-*00 series) and 2- channel output devices (STK401-*00 series). The output load impedance is 6/3Ω. 20W+20W+20W Amplifier Circuit diagram

Indeed the accu charger circuit , the voltage required must be in accordance with voltage batteries , such accu 12 volts the the output voltage should not be above 12 volts and 12 volts should not be too down. If it does not comply with the required voltage , it will make the batteries or accu quickly broken. But not to worry to find the right voltage to charge to accu, the voltage control circuit is equipped to facilitate in determining the voltage. Transformer Primary : 33 turns #22 Secondary : 45 turns #22 Core : Ferroxcube 203 F 181.3C3

This is the simple Personal alarm Circuit Diagram. Small, portable, anti-bag-snatching unit Also suitable for doors and windows control Circuit diagram Parts: R1 330K 1/4W Resistor R2 100R 1/4W Resistor C1 10nF 63V Polyester or Ceramic Capacitor C2 100µF 25V Electrolytic Capacitor Q1 BC547 45V 100mA NPN Transistor Q2 BC327 45V 800mA PNP Transistor SW1 Reed Switch and small magnet (See Notes) SPKR 8 Ohm Loudspeaker (See Notes) B1 3V Battery (two A or AA cells wired in series etc.) Device purpose: This circuit, enclosed in a small plastic box, can be placed into a bag or handbag. A small magnet is placed close to the reed switch and connected to the hand or the clothes of the person carrying the bag by means of a tiny cord. If the bag is snatched abruptly, the magnet looses its contact with the reed switch, SW1 opens, the circuit starts oscillating and the loudspeaker emits a loud alarm sound. The device can be reverse connected, i.e. the box can be placed in a pocket and the cord connec

Transistor Substitution Chart Transistor Switcher

This first circuit is designed by me to replace the mechanical switches used in some thermal Electric I have heaters.The electrical contacts to these mechanical thermal switches are always stoned and “no longer be trusted.”They could easily be welded together, the maintenance of these heating on full. It is definitely not good! Coarse adjustment of the temperature is a trimmer on the track, set to give a nominal range When using the fine adjustment. It is quite difficult in a D-53, manufactured by NEC. The plumb line that is not isolated to the body of the thermistor is arranged. Why is it when you use the wire must be insulated to withstand the high temperatures such as fiberglass insulation against pipe. Thermostat  Circuit Diagram: What is the size of the thermistor is the disk diameter 7 mm and a thickness of 2 mm. The end temperature control is a standard isolated potentiometer with a knob and / or good Protection against electric shock. Harter can be adjusted with this contr

TOUCH SENSITIVE POLICE SIREN CIRCUIT Here we are going to discuss about Touch sensitive siren Circuit. I hope you enjoyed my previous post about RF REMOTE CONTROL AND SWITCHING CIRCUIT. As the Name of this circuit indicates, it is sensitive to our touch. The circuit will generate a siren, similar to police siren, when someone touch across the end terminals A and B. The circuit keeps ALARM as long as the touch. Read More.....

Samsung looks to have taken the humming world of personalised tech gadgetry by surprise today by officially launching the highly rumored, but quite secretive, Samsung SCH-W789 Android-based flip phone in China on Wednesday. Samsung has simply branded the phone with its model number without giving it any personality, unlike the Samsung Galaxy smartphones that received attention akin to the birth of the Catherine, Duchess of Cambridge, and husband Prince William's royal child in Britain recently. Samsung SCH-W789 will be available for the China Telecom users for about $800.  Features wise, Samsung SCH-W789 Android flip phone comes with dual 3.3 inch HVGA touch screen displays with the resolution of 320x480 pixels. It is running Android 4.1 Jelly Bean operating system version and it is powered by a 1.2GHz Qualcomm Quad Core processor along with 1GB of RAM memory. It is a dual SIM device with CDMA + GSM support with dual-standby features. Connectivity features of the phone include Blu

The Simple LED Driver Design TCA62735AFLG is a charge pump type DC DC Converter specially designed for constant current driving of white LED. IC can outputs LED current 120mA or more to 2.8-4.2V input. IC observes the power-supply voltage and the output voltage, and does an automatic change to the best of step up mode 1, 1.5 or 2 times. It is possible to prolong the battery longevity to its maximum.This IC is especially for driving back light white LED s in LCD of PDA, Cellular Phone, or Handy Terminal Equipment. LED Driver Design Circuit Diagram   This electronic project t LED driver is very simple and require few external electronic parts. Due of simplicity of this circuit this project not require additional explanations . If you want to change this design , please consult the manufactured datasheet. Some features of the TCA62735AFLG electronic project are Switching Frequency : 1MHz(Typ.), Output Drive Current Capability : Greater than 120mA , 4 Channels Built in Constant Sink Curre

With LM4651 & LM4652 The combination of the LM4651 driver IC and the LM4652 power MOSFET Class D power amplifier IC provides a high efficiency amplifier solution, suitable for self-powered speakers, subwoofers and quality car boosters . The LM 4651 is a fully integrated conventional pulse width modulator (PWM) driver, containing undervoltage, short circuit, overmodulation, and thermal shutdown protection circuitry. The IC features a standby function which shuts down the pulse width modulation, minimizing supply current. The LM 4652 is a fully integrated H-bridge Power Mosfet IC in a TO220 power package. The IC has a built in temperature sensor to alert the LM4651 when the die temperature exceeds the threshold limit. Used together, the LM4651 and LM4652 form a simple, compact, efficient, high quality power audio amplifier solution complete with protection, normally seen only in Class AB amplifiers. The maximum efficiency of this circuit is 85% at 125W with a standby attenu

A relay is an  electrically operated switch . Current flowing through the coil of the relay creates a magnetic field which attracts a lever and changes the switch contacts. The coil current can be on or off so relays have two switch positions and most have  double throw  ( changeover ) switch contacts as shown in the diagram. Relays allow one circuit to switch a second circuit which can be completely separate from the first. For example a low voltage battery circuit can use a relay to switch a 230V AC mains circuit. There is no electrical connection inside the relay between the two circuits, the link is magnetic and mechanical. The coil of a relay passes a relatively large current, typically 30mA for a 12V relay, but it can be as much as 100mA for relays designed to operate from lower voltages. Most ICs (chips) cannot provide this current and a transistor is usually used to amplify the small IC current to the larger value required for the relay coil. The maximum output current for the

The circuit consists of power supply and control sections. The power supply section is built around transformer X1, bridge rectifier BR1 and filter capacitor C1. The 50Hz, 230V AC mains is stepped down by transformer X1 to deliver a secondary output of 9V, 300 mA. The transformer output is rectified by the bridge rectifier and filtered by capacitor C1. When the mains is switched on for the first time, pin 3 of IC CD4017 (IC1) goes high and relay RL1 energises to switch on the fan. When mains is briefly switched off using S1 and then switched on, the power to IC1 is maintained by the charge on capacitor C1. At the same time, there is a trigger pulse on the clock input (pin 14) of IC1, which advances the decade counter and relay RL2 energises to switch-on the air-conditioner. Both the air-conditioner and the fan will be turned off if the switch is in the ‘off’ position. Assemble the circuit on a general-purpose PCB and enclose in a suitable case. Fix the unit onto the switchboard. Use re

After finally incubated official version led cube 8x8x8 completed.   This increased use atmega chip 32 for high-speed processor, large memory capacity means that the effect increases.   Here are some pictures of products: Video products:

This is my first post and and this is the first circuit i made. There are many types of circuits for controlling home appliances using TV Remote. In fact I had confused a lot when I am a beginner searching for this type of circuits. The circuit here 555 timer IC to avoid fast switching. you can only switch the circuit after 3 seconds. IR remote sensor IC TSOP 1738 is used for recieving the signal. Normally when no signal is falling on IC3 the output of it will be high.This makes Q1 OFF.When a signal of 38 KHz from the TV remote falls on the IC3 its output goes low.This makes Q1 conduct and a negative pulse is obtained at pin 2 of IC 1 NE 555.Due to this IC1 wired as a monostable multivibrator produces a 4 Sec long high signal at its out put. This high out put is the clock for IC 2 which is wired as a Flipflop and of , its two outputs pin 3 goes low and pin 2 goes high.The high output at pin 2 is amplified to drive the relay .For the next signal the outputs of IC2 toggles state. Result

It's the end of summer and many students are coming out of a brief dip into the professional world  working alongside adults and performing entry level tasks, only to return back to classes in the fall. Some are paid, some are not  some provide both learning opportunities and a chance to build one's network, others less so. Across the board, most students will say that an internship is a better investment of time than sitting at home, or working a regular summer job.  But some students have found summer experiences that are, arguably, better for their careers — especially those students interested in entrepreneurship, not joining corporate life. I asked seven students who participated in Lightspeed Venture Partners' summer fellowship — a program that behaves like a startup accelerator without taking equity from the teams — how the experience compared to a summer internship, and what knowledge they'll be taking back to school. Would you consider a non-traditional summer

Here are a Simple Electronic Schematic Circuit Project of Marker Generator.  The marker generator circuit explained here is a constant- frequency oscillator driving into a CMOS divider chain. Switchable out- puts from the divider chain are selected to drive a pulse generator.  The oscillator is C1a in which R1 biases the IC into linear operation. The crystal determines the basic frequency of operation at 4 MHz in conjunction with C1, 2, 3 and 4 which appear to the crystal as one parallel capacitor. Simple Marker Generator Circuit Diagram: The capacitor C2 is  used to tune the oscillator exactly to frequency as explained in the text. The resistor R2 adds extra phase shift but also reduces the gain. Thus if the oscillator is slow in starting reducing R2 may help. The output of the oscillator is buffered from the rest of the circuit by IC1 /b. lC2 is a CMOS dual type D flip flop that divides the 4 MHz by four to provide an out put of 1 MHz, the 2 MHz also being brought out.  A further dua

This is a circuit for a battery charger with automatic overload protection feature . The power supply is 9V and is stabilized by a voltage regulator IC LM317 . The regulator output is used to charge the 6V battery . Once the battery is fully charged (ie the voltage across the battery is 6V ) enters the zener diode biased and starts conducting , which gives a positive voltage to the base terminal of BC548   loading.  Battery Charger with Protection Circuit Diagram

The schematic above can be used for supply on color TV for all type TV circuit. But we need to know how much voltage needed by the circuit of color Television. To set the output voltage, the setting on VR1 1K ohm. Required input voltage 300V DC which is already on TV circuit, so we just take a 300V dc voltage existing on the TV circuit, and for a circuit supply voltage on our TV cut the line PCB and connected with this  universal switching power supply.For the transformer we can use the TV regulator transformer. Part List : R1 = 33R 5W R2 = 330R 1W R3 = 2K2 R4 = 47K R5 = 2K7 R6 = 22K R7 = 390K R8 = 47R 1W C1 = 100uF 25V C2 = 1n2 2KV C3 = 18n C4 = 18n D1 = 1N4148 D2 = 1N4148 D3 = ZD 12V D4 = 1N4007 D5 = 1N4007 VR1 = 1K ZD1 = Zener 6V T1    = TV regulator transformer Q1   = K2847 Q2   = C2328A PCB line Finishes circuit

Build a Elementary IC MonoStable Multivibrator Circuit Diagram. This is a simple Multivibrators have two distinct electrical states, an output "HIGH" state and an output reduced" state giving them either a stable or quasi-stable state counting upon the kind of multivibrator. One such kind of a two state pulse generator configuration are called Monostable Multivibrators . Elementary IC MonoStable Multivibrator Circuit Diagram

This is a simple Electronic Touch Triggered Bistable Circuit Diagram . This circuit uses a 555 timer in the bistable mode. Touching T2 causes the output to go high; D2 conducts and D1 extinguishes. Touching T1 causes the output to go low; D1 conducts and D2 is cut off. The output from pin 3 can also be used to operate other circuits ( a triac controlled lamp). In this case, the LEDs are useful for finding the touch terminals in the dark Cl is not absolutely necessary but helps to prevent triggering from spurious pulses. Electronic Touch Triggered Bistable Circuit Diagram