|
Time to Dust - I have used the circuit below for many different applications, which require ultra low power drain. it uses a single CA4013 flip/flop. One section forms a pulse generator. The generator produces 100uS pulses at a rate of about 1 per second . . . Hobby Circuit designed by Dave Johnson P.E.-May, 2006
Timebase generator - One Minute/One Second Pulse generator. ideal to be used to build any clock. Uses a 12F629. __ Designed by Jose Pino
Timer for Darkroom Camera Shutter - This circuit was designed to control a film exposure shutter for a darkroom. it has 8 time steps ranging from 0.35 seconds to 4 seconds. it is activated by a foot switch and draws power from an external 12-volt DC supply . . . Hobby Circuit designed by David Johnson P.E.-June, 2000
Timers Generate Variable-Sweep Frequencies - 08/01/96 EDN Design Ideas: The circuit inFigure 1 generates a 4- to 5-kHz output frequency that precisely sweeps a variable amount of 1 to 100 Hz over a variable time of 0.5 to 5.0 sec (1000-to-1 rate range). The resolution is 1 Hz, and worst-case accuracy during the sweep is 3 Hz (0.06%). This circuit was designed to run from an 8-bit PC iSA bus, but any µC with an 8-bit bus and the appropriate control signals can control the circuit. Design by D Hayden, Hayden Electronics Design, San Diego, CA
Tiny Crystal Oscillator using LP2980 - High-stability gate oscillator uses two, 5-pin SOT packaged devices. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Touch Activated Switch - This circuit provides about one watt of non-isolated DC power for an automotive type 12v LED array lamp in addition to a standard incandescent table lamp.. . . Circuit by David A. Johnson P.E.-January, 2002
Transconductance Amp Gives Oscillator Reciprocal Response - 17-Apr-03 EDN Design Ideas: High-side current sensor monitors negative rail - The circuit in Figure 1 is a variation on the familiar integrator/comparator triangle-wave oscillator, which you typically implement with two op amps. An integrator and a comparator connect in a positive-feedback loop; the comparator drives the integrator and vice versa. A fixed amount of hysteresis exists in the comparator, producing a triangle wave at the integrator's output Design by Mike Irwin, Shawville, PQ, Canada
Transistor Organ - This simple circuit can provide hours of enjoyment as you learn tunes, play duets or just make some really weird sounds by pushing all the buttons at once. You have probably seen this circuit before, it is fairly common. I have seen it in several __ Designed by Aaron Cake
Triangle & Square Wave Generator - Here is a simple triangle/squarewave generator using a common 1458 dual op-amp that can be used from very low frequencies to about 10 Khz. The time interval for one half cycle is about R*C and the outputs will supply about 10 milliamps of current. Triangle amplitude can __ Designed by Bill Bowden
Triangle / Square wave generator - Transistor Q1, a 2N3563, and its associated components form an oscillator circuit that will oscillate if, and only if, a good crystal is connected to the test clips. The output from the oscillator is then rectified by the 1N4148 signal diode and filtered by C3, a 100pF capacitor. __ Designed by Izhar Fareed
Triangle Signal Generator - A Discover Circuits visitor needed a variable low frequency triangle signal generator, which would produce a full 5 volts peak to peak signal using a 5v supply. I suggested the circuit below. it uses three rail to rail op amps (2 LMC6484 dual op amp packages). The first circuit produces a clean 2.5v reference voltage. The second is configured as a classic multivibrator oscillator . . . Hobby Circuit designed by Dave Johnson P.E.-September, 2011
Triangle Wave Generator - This triangle wave generator is made with a trigger Schmitt that converts a triangle wave into a rectangular one used to charge and discharge a capacitor through current sources. The positive current source T1 provide the charging and T2 the discharging. The trigger Schmitt is made from OR-EXCL gates IC 1a and IC 1b. The __ Designed by Popescu Marian
Triangle waves drive Simple Circuit frequency doubler - 11/23/06 EDN Design Ideas: Extend a function generator's range, and get a sine wave signal in the bargain Design by Jim McLucas, Longmont, CO
Turn D-Flip/Flop into a One Shot Circuit - Yes you can use cheap D flip/flop logic circuits as nice one-shot pulse generators. This schematic shows how the popular CD4013 and the CD74HC74 can be used to generate pulses ranging from nanoseconds to seconds . . . Hobby Circuit designed by Dave Johnson P.E.-June, 2000
Twin-T Audio Sine Wave Oscillator - This circuit produces a clean sine wave signal ideal for audio testing, or wherever a good-quality sine voltage source is required. it uses only one integrated circuit which is a common dual operational amplifier, the Texas instruments TL072CP. The values shown provide an output frequency of about 1000 Hertz. This frequency may be varied over a wide range, using the formula shown in the schematic. For most audio frequencies, the oscillation rate is almost exclusively determined by __ Designed by Arthur Harrison
Twin-T oscillator - This circuit produces an extremely low distortion sine wave, in spite of the non-linear devices used for amplitude limiting (D1 and D2). The reason is first that distortion (harmonics) is fed to the minus input of the OpAmp with far less loss than to the __ Designed by Andrew R. Morris
Twin-T Rc Notch Filter - The two T-notch filter can be used to block unwanted frequencies or if placed in an op amp as a bandpass filter. the notch frequency occurs where the capacitive reactance equals the resistance (Xc = R) and if the values are close, the attenuation can be very high and the notch frequency virtually eliminated, insertion of__
Two DDS ICs implement Amplitude shift keying - 12/25/03 EDN Design Ideas: Many communications systems, including RFID systems and cable modems, use AM (amplitude modulation]. This design idea shows how two DDS (direct-digital-synthesis] devices can implement AM and ASK (amplitude-shift keying] over a range of frequencies. The AD9834 complete 50-MHz DDS IC (Figure 1) has a current output, so you can easily sum the outputs of two orof them by connecting them to a Design by Noel McNamara, Analog Devices, Limerick, Ireland
Two Stage Chaotic Colpitts Oscillator for the UHF range - Chaos in the Colpitts oscillator was first reported at the kilohertz frequencies [1]. Later the circuit was investigated in the high frequency (HF: 3 to 30 MHz) range [2, 3]. Chaotic oscillations were demonstrated. __
Two Tone Audio Oscillator - Circuit Only __ Contact Peter Parker VK3YE
Two-Tone Siren - This circuit is intended for children fun, and is suitable to be installed on bicycles, battery powered cars and motorcycles, but also in models and other games. With SW1 positioned as shown in the circuit diagram it reproduces the typical dual tone sound of Police __ Contact Flavio Dellepiane, fladello @ tin.it
Two-Tone Train Horn - With this circuit you can electronically simulate the noise of a diesel-train horn. The sound is triggered automatically as the train reaches a desired place on the track so you can produce the sound as the train approaches stations, level crossings, etc. The circuit can be built simply by using one 556 or two 555 timers __ Designed by Tony van Roon VA3AVR
Ultra Low Current Oscillator - Here is a challenge. Design an astable oscillator which draws only a few nanoamps of current from a +3v supply. I gave this some thought and came up with the circuit below. I used some pretty standard parts except for three surface mounted 1000M resistors I had on hand. The oscillator frequency measured a low 1Hz frequency and the average current was a very low 3 nanoamps. if I had some higher resistors values handy, I think I could have gotten the current down below one nanoamp. . . Circuit by David A. Johnson P.E.-March, 2009
Ultra Low Current Oscillator #4 - The circuit below was inspired by a programmable unjunction transistor (PUJT) circuit sent to me by Karl isbrecht. in Karl’s circuit, the unijunction circuit made click sounds in a speaker and consumed very little power. His circuit reminded me that a PU. . . Circuit by David Johnson P.E.-January, 2010
Ultra Low Power 32Khz Crystal Oscillator - I have used this circuit many times when I needed a low frequency reference, which did not draw much power. With the components show, the current from a 3v battery is less than 1.2 microamps . . . Hobby Circuit designed by David Johnson P.E.-December, 2004
Ultra Low Power Astable Multivibrator - Taking advantage of some new voltage comparators, this circuit can produce a nice square wave signal while drawing only 1.6 micro amps. With the inclusion of a diode, the circuit can also produce short pulses instead of a square wave signal. . . Circuit by Dave Johnson P.E.-December, 2004
Ultra Low Voltage Crystal Oscillator using Active Loads - Circuit ideas for Designers App Note__ Advanced Linear Devices, Inc
Ultra Low Voltage Micropower Crystal Oscillator - Circuit ideas for Designers App Note__ Advanced Linear Devices, Inc
Ultra Low Voltage Nanopower LC Colpitts Oscillator - Circuit ideas for Designers App Note__ Advanced Linear Devices, Inc
Ultra Lower Power Oscillator - This circuit works much like the classic 555 timer, but draws only about 1.5 microamps from a 3 volt battery. it is highly stable under varying temperature and supply voltages. . . Circuit by David Johnson P.E.-May, 2000
Ultra Pure 125kHz Sine Wave Signal Source - For some RFID systems operating at 125KHz, a very low distortion signal source reference is needed. The circuit shown on this page produces a 10-volt peak-to-peak signal into a 50-ohm load, with a distortion of only 0.01%. . . Circuit by Dave Johnson P.E.-February, 2002
Use an Op Amp as a Set/Reset Flip-Flop - 05/24/12 EDN Design Ideas: Eliminate a flip-flop package by using a spare op amp for an SR latch function. You can make a set/reset flip-flop from two NAND or NOR gates or use readily available set/reset flip-flop IC s, such as the 74HC279 quad-set/reset latch. The drawback of these methods is that they require a large amount of space to form the flip-flop. Even if you need only one flip-flop, you must use a large IC package with this approach. However, you can use a spare rail-to-rail op amp to perform the needed latch function (Figure 1). Design by Aruna Rubasinghe
Use of the CMOS
Unbuffered Inverter in Oscillator - Texas instrument Application ReportSZZA043 January 2004 __ Designed by Moshiul Haque and Ernest Cox
Using the ESG-D RF Signal Generator's Multicarrier, Multichannel CDMA Personality for Component Test, Option UN5 - Application Note__ Aligent |
