Vacuum Tubes Valves
Musical & effects
Yagi Uda Antennas
Metal Detector Circuits
Liquid Sensing Circuits
Light Sensing Circuits
Voltage Detector Circuits
Air-Gas Detection Circuits
Human Sensing Circuits
RF & Radiation
Optical Sensing Circuits
Free Energy Circuits
AC to DC & DC to DC
Solar Cell Circuits
Micro Power Circuits
Switching Power Supplies
Light Laser LED
Digital to Analog
Analog to Digital
Data Bus Circuits
Voltage to Pulse
Current to Voltage
Frequency to Voltage
RF Converter Circuits
Sine to Square Wave
Voltage to Current
voltage to frequency
Period to Voltage
Video Wall circuits
TV Video Circuits
Motor Control Circuits
8051 / 8052
PCB CAD Software
Car bike Circuits
555 Timer Circuits
Remote Control Toy
H Bridge Circuit
Interconnection & Timing
Digital Signal Integrity
Digital & Bipolars
Sensors & Detectors
Regulated Power Supply
4 Band Resistor
5 Band resistor
6 Band resistor
Logic probe yields three discrete states
The circuit uses a dual LED. When power is applied to the probe throughthe power leads, and the input is touched to a low level or ground, Ql is cut off. This will cause Q2 to conduct since the base is positive with respect to the emitter. With Ql cut off and Q2 conducting, the green diode of the dual LED will be forward biased, yielding a green...
The injector is a CMOS oscillator with period approximately equal to 1 x Cl x R2 seconds. The values are given for 1 kHz operation. Resistors R3 and R4 divide theoutput to 1 V; Whereas the oscillator employs the gates in their digital mode, the tracer used them in a linear fashion by applying negative feedback from output to input. They are used...
The unit has a separate amplifier and oscillator section allowing them to be used separately if need be. The injector is a multivibrator running at 1 kHz, with R5 andR6 dividing down the output to a suitable level (Â«1V). The tracer is a single-stage amplifier that drives the high impedance earpiece
Cmos logic probe
The logic probe can indicate four input states, as follows: floating inputâ€”all LEDs off
100K megohm DC probe
A 741 op amp is used with 100% ac and dc feedback to provide a typical input impedance of 1011 ohm and unity gain. To avoid hum and rf pickup the input leads should be kept as short as possible and the circuit should be mounted in a small grounded case. Output leads may be long since the output impedance of the circuit is a fraction of an ohm
Transistors Q1 and Q2 form a buffer, providing the probe with a reasonable input impedance. Q3 and Q4 form a level detecting circuit. As the voltage across the base-emitter junction of the Q3 rises above 0,6 V the transistor turns on thus turning on Q4 and lighting the red (high) LED. Q5 and Q6 perform the same function but for the green (low)...
Logic test probe with memory
There are two switches: a memory disable switch and a pulse polarity switch. Memory disable is a push-button that resets the memory to the low state when depressed. Pulse polarity is a toggle switch that selects whether the probe responds to a high-level or pulse (+5 V) or a low-level or pulse (ground)
The probe indicates a high or low at 70% and 30% of V+ (5 to 12 V). One section of the voltage comparator (LM393) senses V in over 70% of supply and the second section senses V in under 30%. These two sections direct-drive the appropriate LEDs. The pulse detector is a CMOS oneshot (MC14538) triggered on the rising edge of the LM393 outputs...
Audio-rf signal tracer probe
This economical signal tracer is useful for servicing and alignment work in receivers and low power transmitters. When switched to RF, the modulation on any signal is detected by the diode and amplified by the FET
Ttl logic tester
Gates Gl and G2 together with resistors Rl and R2 form a simple voltage monitor that has a trip point of 1 volts. Gate G3 is simply an inverter. The display section of the tester consists of a common anode alphanumeric LED and current-limiting resistors
The low Rds and high peak current capability ofthe DG419 makes it ideal for discharging anÂ·integrator capacitor. A high logic input pulse disconnects the integrator from the analog input and discharges the capacitor.
When a large number of channels are multiplexed, the outputs of two or more multiplexers can be connected together and each multiplexer sequentially enabled. In the inhibit mode. the multiplexer draws less power and its output and inputs act as open circuits. Theoretically, an infinite number of channels can be accommodated in this way; in...
This circuit reconstructs and separates analog signals which have been time-division multiplexed. The conventional method, shown on the left, has several restrictions, particularly when a short dwell time and a long, accurate hold time is required. The capacitors must charge from a low-impedance source through the resistance and...
This circuit shows a typical multiplex system intended to carry one of 8 inputs into a remote location. A 5-V pulse train is sent down a separate channel to perform timing and synchronizing functions. A 15-V reset pulse is superimposed on the 5-V clock, which is detected by the MM74COO in the receiver.
The probe relies on the power supply of the CUT (circuit-under-test). The input to the probe, at probe tip, is fed along two paths. One path flows to the clock inputs of U2a and U2b. The other path feeds both the inverting input of Ulc, which is set up as an inverting-mode integrator, and the noninverting input of Ulb, which is configured as...
The pulser generates pulses at a user-selected frequency of 0.5 or 500 Hz, with a pulse width of about 5 ms. If the input to be pulsed is already being driven high or low by another output, the pulser automatically pulses the input to the opposite logic state.
Digital Levels Scope Displays 2 Logic Signals On 1 Scope
Using this simple resistor circuit, you can trick your oscilloscope into displayin
The HA-4900 series comparators can be used as versatile logic interface devices, as shown in these circuits. Negati
Fast Binary Adding Circuits
Some circuits that add binary numbers have problems with time delay caused by carry propagation. This has been
Universal Test Probe
The compact test probe provides rapid "measurement" of voltage levels at digital gates, fuses, diodes, batteries, and
S1Ngle-Ic Logic Probe
This logic probe uses a CD4009 CMOS hex inverter. The characteristic high-input impedance of CMOS gives the advantage
Â· This circuit is used for analog signal selection or time division multiplexing. As shown, the feedback signal places the selected amplifier channel in a voltage follower (noninverting unity gain) configuration, and provides very high input impedance and low output impedance. The single package replaces four input buffer amplifiers, four...
Multi-Tester Logic Probe Signal Tracer And Injector
This circuit for a test set contains a signal injector (U1A/U1B) and associated com
555 tri-state acousto-optical logic circuit
As illustrated, 555 and R4, R5, C1 and so connected as a controllable multivibrator mode, which force reset terminal 4 feet to explore pen, control terminal 5-pin external level high and low logic level input related.
Door light emitting logic circuit with CD4069
Logic pen also known as logic detection probe, it is a common tool in the digital circuit detection logic state of each point. Digital circuit logic state is generally divided into three types: namely, a high level "l", the low level "0"
LED display driver circuit a
As shown in Figure is a large high-brightness LED driver circuit for a sufficient drive current, integrated circuits using a 7447A or 74247. Digital display tube has eight ligh
LED display control circuit diagram of a counter
As shown, in FIG a decimal seven storage - Decoding - drive unit 74 143, this unit has a constant output for all segments. Each at a voltage of 5V when the current is about 15
High Speed Logic Astable Multivibrator (MC74HC04)
The MC74HC04 IC is a low cost CMOS Hex Inverter. I used this type mainly because, it is what I have, although you can use LS type but, with a little modification or exemptions..
16-bit adjustable reference uses 8-bit digital potentiometers
It may be easy to find a precision voltage reference for your application; however, a programmable precision reference is another matter. The circuit in Figure 1 yields a precision reference with an LSB of 62.5 µV. The circuit is a 16-bit DAC using three 8-bit digital potentiometers and three CMOS op amps. Each digital potentiometer operates as...
5V logic pulser is battery-powered
A battery-powered, pushbutton-triggered TTL/CMOS-compatible source of debounced 5V logic pulses is a simple but handy piece of test equipment to have in any tool kit (Figure 1). The circuit`s battery-powered operation complicates what would otherwise be a trivial exercise in switch-bounce and timing-circuit design. The convenient use of battery...
Build a PIC controlled DDS VFO, 0 to 6 MHz
Almost any 2x16 character LCD module with Hitachi HD44780 controller chip will work. The LCD pin numbers on the schematic are not valid for all LCD modules. Please check the actual signal names on your particular LCD module. The selected DFCW frequency offset will be added to the output frequency when the DFCW input is grounded. This input has a...
The 6090 Digital Decoder
This is an image Schematic. No Description available.
Digital to Analog Circuits
Analog to Digital Circuits
Data Logging Circuits
Data Bus Circuits
Geiger–Müller meter circuit project
In this page we will show how you can simply construct such a meter, which is good to have one, to show not only the existence of radioactive materials but also the dangers arising from them. The Geiger–Müller counter can be compared to a photometer. The photometer measures the visible radiation. That is, light, while the gm meter measures the...
255W Valve RF Transmitter circuit
This transmitter of 255W is depended on the coils we put at it to work in both the middle and the short waves. The power in the antenna is 255W and includes 4 states. The first consists of the EF80 that works as a COLLPITS CLAPP oscillator. Frequency selection is done in a somewhat unusual way: Instead of the variable capacitor, it uses a...
Arduino DAC Signal Generator project
Once the circuit gets current, all variables are initialized and the loop function is continually running. Initially all LEDs are off and there is no signal at the output. By pressing the signal switch, the first light that shows the most signal is at the output and the D0-D7 terminals give the appropriate signal which, when passing from the...
Recording circuit of phone conversations using PC
This circuit is used to record telephone conversations on your landline telephone. All you will need is this small circuit and subscription of your PC. There are few times when we forget what we said or told us. So we need recording. Sometime, not many years ago, recording of this kind of conversation was done with a small tape recorder. The...
FM Micro-Transmitter Bug Surveillance Circuit
The transmitter we recommend to build is quite simple. It can even be built by a beginner. However, unlike the ease of construction and its small size, it is almost certain that it will impress you with its outstanding performance. Its autonomy is 12-15 hours, with a 9 volt battery and its range is from 100 to 300 meters depending on the...
Construction of 50Watt 8Ω two-way Hi-Fi Speakers
The presented speakers are distinguished for their small dimensions and their extraordinary sound. Our home space is often limited and prohibitive for large speakers. This limitation does not mean that we will stay without high Sound Quality. Its design is simple, low cost and is easy to construct. Speaker types are too many and are designed in...
GSM modem circuit with Wavecom WMOi3
Modems are devices that connect either remote devices to a computer, or two or more computers to each other. Their connection is usually wired. The GSM modem we present is wireless. It can connect two computers, a computer with the internet or even be the central unit for a data acquisition system. Generally the construction is a GSM phone...
1W UHF Linear Amplifier with BLW33
This circuit is an amplifier for small transmitters operating in the UHF band, specifically in the 450-800MHz range. The amplifier works in class A and we used the well-known Philips BLW33 transistor for its manufacture. The construction, although simple, can be said to be quite critical due to the high frequency singularity. To achieve this, a...
8W Amplifier with TDA2003 circuit
Many times a small amplifier is needed to meet the needs of small spaces. This amplifier can be either mono or stereo, with this circuitry you can comfortably drive two small speakers. To build the amplifier you do not need anything but a few materials and a small power supply. The power of the amplifier, although low power, will solve many...
Digital Signal Integrity
Interconnection and Timing of Digital Circuits
CMOS Circuits Tutorial
LEGO logic rocks marketing automation
Jul 28, 2017
Alleged iPhone 8 logic board schematics leaks out, here's what it's telling us
Aug 10, 2017
Wattstopper Architectural Dimming and Human Centric Lighting Solutions Accepted into the 2017 IES Progress Report
Aug 18, 2017
Yale launches 'Assure Lock SL' Key Free Touchscreen Deadbolt, HomeKit support module incoming
Jul 25, 2017
Netlist (NLST) and QuickLogic Corporation (QUIK) Head to Head Comparison
Aug 22, 2017
Day: August 21, 2017
Aug 21, 2017
SMARC 2.0 Creates a New IoT Playing Field
Aug 21, 2017
Advancing Connected-Car Technology Through Linux
Aug 17, 2017