This project is sourced from another site, not written by us — this list is our best match of their components against what we stock, not a verified bill of materials. Always check the original blog (linked above) for the actual parts list before buying.
This list includes a generic resistor set
as a placeholder — it is not matched to the exact value or part number this circuit needs. The correct one is specified on the original source page linked above; check it before buying.
The DIY sawtooth waveform generator circuit relies primarily on the versatile NE555 timer IC operating in an astable configuration to create a continuous, repeating ramp signal. Power is supplied to the circuit via a 12V battery or adapter, stabilized by 0.1uF ceramic disk capacitors (C2-C5) which act as decoupling elements to filter out high-frequency noise from the power rails. The core timing mechanism involves the charging and discharging of the large 100uF 35V electrolytic capacitor (C1). By utilizing a 1N4148 signal diode (D1) alongside the 56k ohm resistor (R1), 1k ohm resistor (R2), 10k ohm resistor (R3), and a 100k ohm potentiometer (VR1), the circuit controls the current flowing into capacitor C1. The diode and potentiometer network forces the capacitor to charge up relatively slowly and linearly, producing the gradual upward slope of the sawtooth wave, before discharging more rapidly to reset the cycle. As C1 charges and discharges, the internal threshold and trigger comparators of the NE555 monitor the voltage, switching states accordingly at the output. The resulting signal can then be easily accessed through the 2-pin connectors (CON1 and CON2) for various external testing and measurement applications. Whether built on a temporary breadboard or a permanent general-purpose PCB, this analog configuration provides a reliable and adjustable ramp output without requiring any programmable microcontroller or software.
Why Build This
Design and analyze analog relaxation oscillator circuits using classic timer ICs to deepen undergraduate-level understanding of RC charging curves.
Generate practical sawtooth signals for testing thyristor firing circuits, SCR/triac phase control, and various modulation schemes.
Gain hands-on experience tuning waveform frequency and linearity using variable potentiometers and discrete semiconductor components.
Real-World Application
Thyristor (SCR, triac) switching, sampling, tone and frequency generation, and modulation.
Skills You'll Learn
Analog circuit prototyping
RC timing network calculation
discrete waveform generation
oscilloscope signal analysis
power supply decoupling
Safety Precautions
No specific precautions noted for this build — always follow general electronics safety practices.
Technology Tags
NE555 TIMER
ANALOG ELECTRONICS
WAVEFORM GENERATOR
CIRCUIT DESIGN
BREADBOARD PROTOTYPING
Frequently Asked Questions
The NE555 timer IC typically operates within a 4.5V to 16V range, so standard 9V or 12V DC sources will work, but verify that the 35V rating on electrolytic capacitor C1 is respected for safety.
The 0.1uF ceramic disk capacitors (C2-C5) are not used for timing; instead, they serve as high-frequency bypass or decoupling capacitors placed close to the power pins to stabilize the circuit and prevent unwanted oscillations.
You can adjust the charging characteristics and frequency of the output by turning the 100k ohm potentiometer (VR1), which alters the rate at which the 100uF electrolytic capacitor charges through the resistor-diode network.
Gallery
This page is part of Kitkraft's Project Hub — a curated collection of electronics & robotics projects gathered from the maker community to help students and hobbyists discover and learn to build. Kitkraft does not claim authorship of the original project, and makes no representation as to the accuracy, completeness or safety of third-party source material. The summary and "How It Works" explanation above are AI-generated, rewritten with reference to the original tutorial — not a reproduction of it. Full credit and a direct link to the original source are provided above. If you're the original creator and have a concern about how your work is represented here, please contact us and we'll address it promptly.
Kitkraft Project Hub — curated from the maker community, credited at the source.
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