Ramp Generator Circuit

Dual Ramp Generator
The first circuit is a dual ramp generator where the positive
and negative ramps are generated separately. This circuit
was used as a ramp generator for a transistor curve tracer:
the positive going ramp was used for testing NPN transistors
and the negative ramp for testing PNP transistors.


Generating Triangle Waves
In the circuit to the right, we use a separate integrator to
generate a ramp voltage from the generated square wave.
As a result, we can get both waveforms from a single circuit.
The phase relationship shown between the two output
waveforms is correct


555 ramp generator
Again, we are using a 555 timer IC as an astable multivibrator,
or oscillator. This time, however, we will compare its operation
in two different capacitor-charging modes: traditional RC and
constant-current.


Ramp Generator by Schmitt trigger

Precision ramp generator produces a 0 to 5V ramp

The ramp is generated by a constant charging current into

capacitor CRAMP, which is connected between ground and

the noninverting input of op amp IC1, configured as a

voltage follower. The current through RRAMP is the charging

current, kept constant by forcing the voltage across RRAMP

to equal the reference voltage from IC1. One side of RRAMP

is connected to CRAMP, and the other side to the reference

output. In turn, the ground terminal of the reference IC connects

to the op-amp output, which provides a low-impedance replica

of the voltage across CRAMP

Linear Voltage Ramp
To make the ramp of the charging cycle linear with time the

capacitor must be charged from a constant current. R1 is

replaced with another PNP Q3, which implements a constant

current source. Q3's base voltage is fed from a diode drop,

leaving just a single resistor R1 to vary the charging current,

and hence frequency of oscillation.

Pulse Generator Circuit

Transistor Schmitt Trigger Oscillator
The Schmitt Trigger oscillator below employs 3 transistors, 6
resistors and a capacitor to generate a square waveform.
Pulse waveforms can be generated with an additional diode
and resistor (R6). Q1 and Q2 are connected with a common
emitter resistor (R1) so that the conduction of one transistor
causes the other to turn off. Q3 is controlled by Q2 and
provides the squarewave output from the collector.


X'tal Oscillator Frequency
This circuit may used as clock frequency for many digital
circuits. I got this circuit from a microcontroller clock generator

555 Pulse Generator
A 555 pulse generator circuit with a difference, the initial

pulse is tailored by additional circuitry to match the duration

of subsequent pulses.

Op Amp Square Wave Generator
This is a square wave generator circuit. The main component

of this circuit is the 741, a general-purpose operational amplifier.

This circuit employs a single power supply Vs that can range

from +5V to +15V.

Changing the pulse width
The previous assembly gives a rectangular signal with a duty

cyclic equal to 50 %. We can need to change it to produce

pulses for example. A simple means is to use a variable RC

circuit and to reshape the signal obtained by means of a

Schmidt trigger , here a CD 4093 which allows to use a wide

range of voltage.