Matt circuit

The 555 circuit below is a flashing bicycle light powered with four C,D or AA cells (6 volts). Two sets of 20 LEDs will alternately flash at approximately 4.7 cycles per second using RC values shown (4.7K for R1, 150K for R2 and a 1uF capacitor). Time intervals for the two lamps are about 107 milliseconds (T1, upper LEDs) and 104 milliseconds (T2 lower LEDs). Two transistors are used to provide additional current beyond the 200 mA limit of the 555 timer. A single LED is placed in series with the base of the PNP transistor so that the lower 20 LEDs turn off when the 555 output goes high during the T1 time interval. The high output level of the 555 timer is 1.7 volts less than the supply voltage. 40 LED Bicycle Light Circuit Diagram   Adding the LED increases the forward voltage required for the PNP transistor to about 2.7 volts so that the 1.7 volt difference from supply to the output is insufficient to turn on the transistor. Each LED is supplied with about 20mA of current...

Here is the simple virtual ground circuit based on discrete components. This simple design comes from miniaturization guru Sijosae. Is to make a buffer from generic discrete components. The transistors can be most any complementary pair of small-signal transistors. Suitable alternatives are the PN2222A and PN2907A. The diodes are generic small-signal types. An acceptable alternative is the 1N914. This circuit has better performance than a simple resistive divider virtual ground, and the parts cost is lower than for any other circuit mentioned here. It is, however, the least accurate of the buffered virtual ground circuits. Discrete Virtual Ground Circuit Diagram     Parts: R1,R2 = 4.7K R3,R4 = 4.7R C1,C2 = 470uF-25V C3,C4 = 47uF-25V D1,D2 = 1N4148 Q1 = 2SC1384 Q2 = 2SA684 B1 = Battery

This is the Simple IC TDA2030 Complete tone Control Circuit Diagram . This circuit that use IC TDA2030, but this series is equipped with a tone control. Tone controls include Bass, Treble, and Volume. Power amplifier and tone control has been put together in a single PCB. This amplifier is a mono amplifier type, can be modify for guitar amplifiers .  If not coupled amplifier (mic preamp) then you must deactivated potensio treble and bass, why? because if not using a mic preamp and still maintain potensio treble and bass sound input (input) from the guitar will not or the maximum discharge is not tight on the speakers . So you must deactivated a way to decide which directly connected capacitor  with the tone control circuit, and capacitor were connected directly to potensio volume and input jack.   TDA2030 Complete Tone Control Circuit Diagram PCB Layout   TDA2030 Complete Tone Control Circuit Diagram PCB

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This is a Simple 1.5V Battery to 5V Voltage Converter Circuit Diagram. Stable and secure 5V DC (at 200mA max) from an ordinary 1.5V AA sized cell. At the heart of this circuit is IC1 MAX756 from Maxim, which is a CMOS step-up DC-DC switching regulator for small, low input voltage or battery-powered systems.   Simple 1.5V Battery to 5V Voltage Converter Circuit Diagram MAX756 accepts a positive input voltage down to 0.7V and converts it to a higher pin selectable output voltage of 5V (or 3.3V). Typical full-load efficiency for the this IC is greater than 87%. Max756 combine a switch-mode regulator with an N-channel MOSFET, precision voltage reference, and power-fail detector in a single monolithic device. The MOSFET is a “sense-FET” type for best efficiency, and has a very low gate threshold voltage to ensure start-up under low-battery voltage conditions (1.1V typ). The circuit can be easily wired on a very small rectangular common PCB.All connections should be kept as short as poss...

This is a simple colpitts clapp 1 to 20Mhz crystal oscillator circuit diagram. The majority of modern crystal oscillator circuits fall into one of two design categories, the Colpitts Clapp oscillator and the Pierce oscillator. This simpie Colpitis crystal oscillator for 1 to 20 MHz, can be easily made from junk-box parts Colpitts Clapp 1 To 20Mhz Crystal Oscillator Circuit Diagram

Using the FAN 7710 Ballast Control IC for Compact Fluorescent Lamps developed using Fairchild’s unique highvoltage process and system-in-package (SiP) concept can be designed a very simple low cost fluorescent lamp driver electronic project .The FAN7710 ballast control controls internal high-voltage stress and delivers 20W to the lamp at 320VDC voltage. FAN7710 ballast control incorporates a preheating /ignition function, controlled by an user-selected external capacitor, to increase lamp life. The FAN7710 detects switch operation from after ignition-mode through an internal active Zero-Voltage Switching (ZVS) control circuit. The AC line input voltage (230 VAC 50 Hz) is rectified to provide a bus voltage of approximately 320 volts DC. Startup resistor R1 supplies initial power to the FAN7710 IC.The IC begins to oscillate and the charge pump circuit consisting of C2, D2 and D7 supplies the current to the VDD pin, which gets regulated through the internal 15-V shunt regulator.

This Outdoor LED Solar Garden Lights project is a hobby circuit of an automatic garden light using a LDR and 6V/5W solar panel. During day time, the internal rechargeable 6 Volt SLA battery receives charging current from the connected solar panel through polarity protection diode D9 and current limiting resistor R10. If ambient light is normal, transistor T1 is reverse biased by IC1 (LM555). Here IC1 is wired as a medium current inverting line driver, switched by an encapsulated light detector (10mm LDR). Multi-turn trimpot P1 sets the detection sensitivity. When ambient light dims, transistor T1 turns on to drive the white LED string (D1-D8). Now this lamp load at the output of T1 energizes. Resistors R1-R8 limits the operating current of the LEDs. When the ambient light level restores, circuit returns to its idle state and light(s) switched off by the circuit. Circuit diagram: Outdoor Garden Solar Lights Circuit Diagram Assemble the Outdoor Solar Lights circuit on a general pur...

Description. Here is a simple charger circuit for charging SMF(sealed maintenance free ) batteries.The charger circuit being curernt and voltage regulated,can be safely used to charge SMF batteries of 1.2 AH rating.This circuit was actually designed in response to a request from a reader.With slight modifications you can use it for charging any sort of SMF batteries. The first part of the circuit is the power supply made of transformer T1 and diodes D1&D2.The capacitor C1 filters the rectifier output .The next part is the section comprising of IC1 and Q1 which provides the necessary volatge and current regulation.The diode D3 prevents ther reverse flow of charge from the battery . Circuit diagram with parts list. Notes. Assemble the circuit on a good quality PCB or common board. An ammeter can be conncted in series with the battery to monitor the charging current. Do not short circuit the charging terminals of the circuit.The circuit doesnot have short circuit protection. R4 is ...

This amplifier output circuit having a fairly low at only 2W 8 ohm impedance. Minimum supply voltage is needed 4 volts and a maximum voltage 18V DC. Power amplifier circuit was very low compared with other PA IC series, an average of 30W and over. Part List : R1 =  750K R2 = 100K R3 = 1K R4 = 18K R5 = 330K R6 = 82K R7 = 10K C1 = 5uF C2 = 100uF C3 = 1000pF C4 = 1000uF C5 = 0.1uF C6 = 5uF U1 = PA246

This is a driver circuit for siren. This circuit usually used for car alarms. To build this circuit, we use VD-MOS FETs. This circuit receives 12 v supply from battery. A microprocessor sends complementary pulse waveforms to the driver circuit as inputs. Here is the circuit : This circuit uses two PHC21025 which each of them contains two FETs. Two BSN20 VD-MOS FETs in small SOT23 packages also used in this circuit. The maximum configuration of this circuit needs eight components and the minimum configuration of this circuit needs six components

This circuit use IC TDA1004A to main operation .IC is very nice and durable if used properly and correctly, by the way supply the correct voltage , don't supply more voltage than 20 volts, because it can damage the IC. This circuit suitable for subwoofer speakers, but this amplifier  is mono.See schematic and troubleshooting below : If the circuit above not working , posible cause is on : Supply voltage. IC Damaged or installation inverted. Component damaged . Installation components inverted. Line break PCB. Input not connected or input connect to ground. Output speaker not connected.

Description AFX slot car sets are very enjoyable but you can increase the fun with a lap counter. This circuit will count from 00 to 99, with independent counters for each track. The sensing device used is a Hall effect sensor (UGN3503; available from Dick Smith Electronics). One of these sensors is glued under a section of each track (printed side up); between the slot and one of the track rails is the best spot. In this position, it will allow the ground effects magnets on the cars to pass over them. The sensor will provide a voltage of about 3V when a car passes over it and about 2V without a magnetic field. Circuit Diagram Both counter circuits are identical, with dual op amp IC5 handling the signals from both sensors. IC5a and IC5b are wired as comparators, with a 2.5V reference derived from zener diode ZD1 via the 10kΩ and 12kΩ resistors. Each time the output of IC5a goes high it clocks IC1a, a 4518 BCD counter. NAND gates IC2a & IC2b provide a carry out to the other half of ...

This is a very simple liquid detector which controls a relay , this gives you the option to be used for hundreds of applications . You can use it as a float switch to turn on the water pump alarm, rain, etc. . He uses a 4093 IC and transistor can be anyone, provided that it meets the power relay . This sensor can be used with Arduino no problem . Sensor and Detector Liquids Circuit Diagram

LA4440 is a dual channel audio amplifier IC. It can be used in two modes; one is Stereo amplifier and another Bridge amplifier mode. The LA4440 is a monolithic linear IC from Sanyo. Here I give the both circuit mode of amplifier using IC LA4440. When the IC LA4440 is in Bridge mode in the circuit, its output power is 19w. In bridge mode use 4Ω-8Ω speaker. If you want stereo output(19w+19w) in bridge mode then use two copies of amplifier circuit of given below. Resistor R3&R4 is to adjust the voltage gain and for making input signal of inverting amplifier. C10 is filter capacitor used to reduce the ripple of supply voltage. Don’t decrease the value of capacitor C6&C7 less than 100uF, 10v, it may causes of the output at low frequencies goes lower. The pin-6 of LA4440 amplifier circuit  is audio input pin; it used in stereo amplifier mode but in bridge mode it is grounded. C8&C9 are polyester film capacitor used to preventing oscillation, and R1&R2 used for the same re...

This Simple Cmos Motorcycle Alarm Circuit Diagram features an intermittent siren output and automatic reset. It can be operated manually using a key-switch or a hidden switch; but it can also be wired to set itself automatically when you turn-off the ignition. By adding external relays you can immobilize the bike - flash the lights etc. Cmos Motorcycle Alarm Schematic Diagram Notes Any number of normally-open switches may be used. Fit "tilt" switches that close when the steering is moved or when the bike is lifted off its side-stand or pushed forward off its centre-stand. Use micro-switches to protect removable panels and the lids of panniers etc. Once activated - the rate at which the siren switches on and off is controlled by R9 & C5. For example - increasing the value of C5 will slow it down - while reducing the value of R9 will make it faster. While at least one switch remains closed the siren will sound. About thirty seconds after all of the switches have been open...

This is the Simple Simulated inductor Circuit Diagram. In the this circuit With a constant current excitation, the voltage dropped across an inductance in-(in creases with frequency. Thus, an active device whose output increases with frequency can be characterized as an inductance. Simple Simulated inductor Circuit Diagram The circuit yields such a response with the effective inductance being equal to: L = R1R2C. The Q of this inductance depends upon Rl being equal to R2. At the same time, however, the positive and negative feedback paths of the amplifier are equal leading to the distinct possibility of instability at high frequencies. Rl should, therefore, always be slightly smaller than R2 to assure stable operation.

Telephone Ringing circuit Diagram . Even though cordless phones have invaded our homes and offices, you don’t always have them at hand, and as their ringtones are usually very much quieter than the old rotary-dial- type analogue phones, it can happen that you miss a call you’ve been waiting for while you’ve been going about your daily business.  Until quite recently, you could still find remote ringers that could be plugged into any standard phone socket in order to have an additional ringer, but it seems as if these accessories are currently being phased out as everyone is ‘going cordless’. So we decided to suggest something better, with this phone ring repeater that makes it possible to control any device connected to the AC power outlet using the ringtone available on any subscriber line, and naturally, with all the guarantees of safety and isolation that are of course rightly expected. So it’s capable of driving a ringer, or indeed even a high-powered sounder to alert you when ...

The article describes a very simple homemade emergency light circuit that can be used during power failures and outdoors where any other source of power might be unavailable. The circuit uses LEDs instead of incandescent lamp, thus making the unit very power efficient and brighter with its light output. Moreover, the circuit employs a very innovative concept especially devised by me which further enhances the economical feature of the unit. We know that LEDs require a certain fixed forward voltage drop to become illuminated and it is at this rating when the LED is at it’s best, that is voltages which is around its forward voltage drop facilitates the device to operate in the most efficient way. As this voltage is increased, the LED starts drawing more current, rather dissipating extra current by getting heated up itself and also through the resistor which also gets heated up in the process of limiting the extra current. If we could maintain a voltage around an LED near to its rated for...

This power supply uses two VN400A 400 Volts  MOSFETs in a half-bridge power switch configuration. Each output consists of +5V at 20 A and 15 V at 1 A . Three-terminal regulators are used for the low-currents outputs , either 12 Volts or 15 Volts can be made available with a simple change in the transformer secondary windings. Schematic diagram below : IC TL494 switching regulator IC provides pulse-with modulation control and drive signals for the power supply , The upper MOSFET , Q7 , in the power switch stage is driven by a simple transformer drive circuit. The lower MOSFET , Q6 , since it ground referenced , is directly driven from the control IC.