Best Function Generators Under $50 (2026)
We selected units under $50 by comparing value scores derived from output types, adjustability, build quality, and relevance to PLC and industrial testing
The Verdict
- Best Overall: DROK 4-20mA/0-10V Dual Signal Generator (2 pcs) — Best for PLC loop testing: dual current and voltage outputs provide flexible 4–20mA and 0–10V simulation in one compact module
- Best Value: Adjustable signal generator 4-20mA 0-12V DC for PLC testing — Best for precise PLC calibration: adjustable 4–20mA and 0–12V outputs with PWM capability for versatile signal sourcing
Top Picks
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1
Best Overall DROK 4-20mA/0-10V Dual Signal Generator (2 pcs)
Best for PLC loop testing: dual current and voltage outputs provide flexible 4–20mA and 0–10V simulation in one compact module
Dual signal generator module outputs 0/4-20mA current and 0-10V voltage with a clear LED display. Useful for PLC testing and troubleshooting; praised for accuracy and ease of use, though build quality and power sourcing receive mixed feedback
- dual amp & volt output
- bright LED display
- back calibration potentiometers
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2
Best Value Adjustable signal generator 4-20mA 0-12V DC for PLC testing
Best for precise PLC calibration: adjustable 4–20mA and 0–12V outputs with PWM capability for versatile signal sourcing
Adjustable signal generator for 4-20mA current and 0-12V DC voltage output. suitable for PLC controller panel testing and LED calibration. customer notes indicate variable output depending on load
- 4-20mA/current and 0-12V DC outputs
- PWM pulse capability up to 150 kHz
- short circuit protection and high precision
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3
Healflux Custom Frequency Generator V2
Best for frequency-focused use: custom frequency output tailored to relaxation and low-frequency applications including Schumann-range signals
A frequency generator offering adjustable sine wave resonance, featuring 7.83Hz Schumann resonance for relaxation and sleep support. Easily tunable from low to high frequencies to fit personal needs
- 7.83Hz Schumann resonance
- wide 0.01Hz–20kHz adjustable range
- ultra-low to high frequency capability