Circuit Wiring Solution: generator

Showing posts with label generator. Show all posts

Tuesday, November 18, 2014

Triangle Square Wave Generator Using Op Amp

The circuit shows a simple triangle and square wave generator with a common dual operational amplifier LM1558 to produce very low frequencies around 10 kHz. The time interval for one half cycle is about R * C and outs of supply of 10 mA. The amplitude of the triangle can be altered by adjusting the 47K and waveform offset can be eliminated by adding a capacitor in series with the output.

Thursday, November 13, 2014

PWM Generator Schematic

PWM waveforms are commonly used to control the speed of DC motors. The mark /space ratio of the digital wave-form can be defined either by using an adjustable analogue voltage level (in the case of a NE555 based PWM generator) or digitally using binary values. Digitally derived PWM waveforms are most often produced by the timer/counter modules in microcontrollers but if you do not want to include amicrocontroller in your circuit it’s also quite simple to generate the signals using discrete logic components. An extension of the circuit shown can pro-duce two PWM waveforms from an 8-bit digital input word. Each signal has 15 val-ues. The 8-bit word can be produced for example from an expansion board fitted in a PC or from an 8-bit port of a processor which does not have built-in PWM capability or from a laptop’s printer port.

Discrete PWM Generator Circuit Diagram

The mark/space ratio is only programmable up to 15/16 rather than 16/16; a binary input of 0000 produces a continuous low on both outputs turning both motors off. Similar circuits often employ a dedicated ‘enable’ input to turn the motors off but it is not necessary in this design.

The diagram shows the circuitry required to produce just one waveform. For the full two channel circuit it is necessary to use an additional 74HC193. The clock signal produced by the HCF4060 generator can be used to drive both channels and the free flip flop in the 74HC74 package can be used for the second channel (the corresponding pin numbers are shown in brackets). Alto-gether the entire two channel circuit can be built using just four ICs.

Friday, October 17, 2014

A Simple Function Generator

This is a simple function generator circuit that can produce the following waveforms: square wave, triangular wave, and sine wave.

The circuits main components are two 1458 ICs. The 1458 is a dual op-amp IC, i.e., an IC that houses two op amps inside it. The circuit uses four op amps, two from each 1458.

The bottom-most op amp in Figure 1 is configured as an astable multivibrator, which continuously generates a square wave. Assume that C1 has no charge initially. The voltage at the inverting input is zero, while the voltage at the non-inverting input is very slightly positive (a ratio of the op amps output offset voltage as determined by R1 and R2). This minute voltage difference at the inputs is enough to cause the op amps output to swing to high.

When the output becomes high, C1 starts charging up. The voltage at the inverting input soon exceeds that at the non-inverting input, forcing the output to swing to low, which discharges C1 again. At a certain point, the voltage at the non-inverting input exceeds that at the inverting input again, and the output of the op amp goes high again.

This cycle wherein the first op amps output swings between low and high goes on indefinitely, generating the square wave.

The two middle op-amps are both configured as integrators. The input to the second op amp is the square wave output of the first op amp. Being configured as an integrator, this op amp outputs a triangular wave (the integral of a square wave), as shown in Figure 1.

The triangular wave output of the second op amp is then fed into the third op amp, which is also configured as an integrator. The output of the third op amp is a sine wave (the integral of a triangular wave).

The sine wave output of the third op amp is fed into the fourth op amp, which is configured as an inverting amplifier. The output of this last op amp is also a sine wave but opposite in phase as its input.

Wednesday, September 24, 2014

Triangular wave form Generator Circuit

A triangular waveform generator can Vi be made by using one amplifier of a LM3900N device as an integrator and another amplifier as a Schmitt trigger circuit.
A suitable circuit is shown, it has the unusual advantage that only the one power supply is required. When the output voltage from the Schmitt trigger circuit is low, the current flowing through Ra is integrated by C; to produce the negative slope of the triangular wave at output 1. When the output 2 voltage from the Schmitt trigger ls high, current flows through R; to produce the rising part of the waveform at output 1. The output waveform will have good symmetry if R1 = ZR;. The output frequency ls given bythe equation: f=V(+) - Vbe/2R1C1V Whel8 R1 = 2Rg, V35 ii the steady voltage at the inverting input (0.5 V) and V is the difference between the tripping points of the Schmitt trigger.

Friday, September 12, 2014

K574UD1 generator audio range

In the development and research of electronic equipment in the laboratory one of the most important components of the measurement equipment is a universal source of test signals. Function generator, working in a range of sound frequencies, was developed based on a microcontroller. It is based on generator circuit described in [Radiohobby, 2000, № 5, p. 79]. The analysis of this scheme it was revealed a significant disadvantage. Because the counter is formed by two functional elements, the logic levels on the address pins are not installed simultaneously, which leads to the appearance of high-frequency emissions of the generator output. Developed device devoid of these deficiencies. Generated output waveform (saw, triangle, sine, square wave) programmed in flash-memory. The generator used firmware contained in [Radiohobby, 2000, № 5, p. 79]. Schematic diagram of the function generator is shown in Fig. 1.

The main technical parameters:

Range of generated frequencies, Hz

0 ... 30000

Flatness dB

<0.3

The amplitude of the output voltage, V

Number of steps output

128 128

MS 4046 on a chip (DD1) assembled an oscillator, which control the frequency tuning in the range 0 ... 4 MHz. Variable resistor R1 is a multiple of the frequency control. On-chip 556IE10 (DD2) assembled address counter which outputs signals are formed ("typed address") applied to the address inputs of the PROM Winbond W27C512 (DD4). In this flash-memory chip programmed forms of output signals. With PROM outputs signals are sent to the DAC DAC0800 (DA4), from which output signal is fed to a high-speed operational amplifier K574UD1 (DA5). SB1 button is used to select the output waveform. The components of the chip 155LAZ (DD3.2, DD3.3) Assemble debounce buttons SB1. With the terminals 5 and 9, which also receives signals from the outputs of the PROM, the signal goes to the chip decoder SN74LS156N (DD7). With its removable data outputs the selected signal that displays one of the LEDs. For indicating the selected output waveform is assembled unit to the D-flip-flop circuits 155TM2 (DD6), the input of which receives impulses originating switching button. The unit is powered from the unregulated voltage source + 12, which enters the integral timer DA1 and positive voltage stabilizer DA2. Timer DA1 implemented multivibrator, the output of which removed rectangular pulses. They are rectified and is input to the negative voltage regulator DA3. The voltage from its output is used to power a generator. When setting up the device you first need to set the frequency of the selection of C1-order 4 MHz at pin 4 chips DD1, then the resistor R11 to generate sine wave mode, controlling the output of an oscilloscope, to establish the symmetry of the signal relative to the total wire. The maximum output frequency of the oscillator is determined primarily by the speed of EEPROM, which for the chip Winbond W27C512 is approximately 4 MHz, so the maximum output frequency: 4 MGts/128 stages = 30 kHz. Measured harmonic distortion of the sinusoidal signal constitute 0.0076% at 1 kHz. This generator is designed to work with a digital oscilloscope, which displays the frequency of the input signal, so additional indication output signal frequency is not provided. The devices made on microcontrollers, promising enough. For example, the proposed generator can be increased through the use of frequency oscillator with greater frequency. Also by increasing the bit of flash-memory can increase the frequency of sampling. The generator can be connected to a PC with the ability to programmatically change the shape of the output signal due to changes in firmware flash-memory. Resistor R1 - SP5-44-1 or other reusable, R9, R11 - SPZZa or other small.
Original article source cxem.net

Tuesday, September 9, 2014

High Frequency Waveform Generator schematic

This is a waveform generator based on IC with wide operating frequency, Maxim MAX038. This IC is able to generate frequency between 0.1Hz to 20MHz.

Here the schematic diagram:

The schema can be used to generate square wave, triangle, or sine wave by programming the pin inputs (A0:pin 3, A1:pin 4).
- A0 A1 WAVEFORM
- X 1 Sine wave
- 0 0 Square wave
- 1 0 Triangle wave
The frequency can be controlled using current. If we disconnect the 20k RIN from REF (pin 1) and connect it to a DAC, then we can control the frequency using microcontroller or digital interface. We can even control the chip using a quartz crystal (PLL) by controlling the current using a phase comparator output that compares the sync output (pin 14 of MAX038) and a reference clock from quartz crystal oscillator.

Just try to build this schema... :)

Monday, September 8, 2014

6V 3W Bicycle Generator System Circuit

6V/3W Bicycle Generator System Circuit

This is a regulator for a 6V/3W bicycle generator system. The purpose is to switch to rechargeable batteries when the generator is idle. In addition, the device limits the voltage across the bulbs when the generator operates at a high speed. As you can see, the schema is purely electrical. In the presented design, the switch has been moved, compared to the original to a location where the switch better functions under different circumstances. I kept the regulator on the bike for 2 years during which the schema operated fairly satisfactorily. Thereafter, I moved on to an electronic regulator optimized for the operation with a hub dynamo.