Variable transformer 500VA from PHC Enterprise, Inc., with adjustable 0–130VAC benchtop model SC-5M, showing control dial and terminals.

Diagram of PHC Enterprise SC-5M variable transformer showing specifications for 500VA, 0–130VAC benchtop adjustable power supply

Variable Transformer 500VA (5 Amp) | 0–130VAC Benchtop - SC-5M

Name: Variable Transformer 500VA (5 Amp) | 0–130VAC Benchtop - SC-5M
Brand: PHC Enterprise, Inc.
SKU: SC-5M
Price: 59.00 USD
Availability: InStock
Rating: 4.69 (32 reviews)

by PHC Enterprise, Inc.

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$72.00

$72.00 - $72.00

$72.00

$59.00

$59.00 - $59.00

$59.00

500VA Variable Autotransformer (5 Amp) | Model SC-5M

The SC-5M is a precision-engineered 500VA variable autotransformer (variac) designed for adjustable AC voltage control on standard 120V bench, lab, and repair-shop circuits. Delivering a smooth, continuously adjustable output from 0 to 130VAC at up to 5 Amps, the SC-5M is a compact benchtop tool for technicians, educators, and product developers.

Why Choose the SC-5M?

Compact Benchtop Footprint: Sized for technician workstations, repair benches, and school lab carts where a full-size 1500VA unit isn't needed.
Real-Time Analog Monitoring: Integrated analog voltmeter gives a quick visual reference as you dial in your target AC voltage.
Rugged & Fuse-Protected: Heavy-duty industrial-grade metal enclosure with a replaceable built-in fuse for overload protection.

Technical Specifications

Type: Single-Phase Non-Isolated Variable Autotransformer (Variac)
Model / Part Number: SC-5M
Input Voltage: 117V AC @ 50/60Hz (Standard US Wall Outlet)
Output Voltage: 0–130V AC (Variable)
Rated Capacity: 500VA (5 Amp Max Continuous Load)
Display: Integrated Analog Voltmeter
Protection: Built-in Fuse (Replaceable)
Weight: 9.5 lbs

Safety & Application Note: The SC-5M is an autotransformer and does not provide galvanic isolation from the incoming AC line. For vintage tube audio, hot-chassis repair, or floating signal applications, explore our isolated variac models, the SC-10T-2 and SC-2T.

Common Applications — Who Is This For?

University & Research Labs: Ideal for engineering education and physics experiments requiring adjustable AC voltage.
Electronics Repair & Service: Power up vintage equipment or test circuits under variable load.
Testing & Calibration: Useful for QC departments verifying power supply tolerances across an AC voltage range.
Product Development: Simulate real-world AC line fluctuations for new device testing up to 5 Amps.

Frequently Asked Questions

Q: Is the SC-5M an isolation transformer?
A: No. The SC-5M is a variable autotransformer, not an isolated variac. It does not separate the output from the incoming AC line, so treat the output as line-connected for safety purposes. If you need galvanic isolation, see the SC-10T-2 or SC-2T.

Q: What is the maximum continuous load I can run?
A: The SC-5M is rated for 500VA (5 Amps) at up to 130VAC output. Stay within this rating and avoid continuous high-load or permanent-installation use, since it's designed for benchtop and intermittent testing use.

Q: How accurate is the built-in voltmeter?
A: The integrated analog voltmeter is useful for quick reference, but for precise voltage settings we recommend confirming actual output with a calibrated multimeter.

Q: Can the SC-5M output more than 130VAC?
A: No. The output range is fixed at 0–130VAC and cannot exceed the incoming 117VAC line beyond its rated adjustment range.

Q: Does the SC-5M accept 220-240VAC input?
A: No. The SC-5M is designed for 117V AC @ 50/60Hz input only. Do not connect it to 220-240VAC mains.

What an INCREDIBLE deal, what service!!! I'm be buying more!

I bought the Variac/isolation transformer combo. FOR STARTERS: NOBODY ELSE MAKES THIS COMBO with a genuine isolation transformer. And that fact that it's $200 out the door is insanity. My only advice with the unit would be to double check the voltage display against a multimeter; I find my display to be about 5V lower than the actual output and adjusted accordingly.

This item was packaged more securely than a nuclear warhead. Seriously, the packing job is a masterclass in transportation and logistical safeguards.

In short--I rarely leave reviews. I felt I HAD to for this product. If you're not sure because it's a newer item/company, don't worry. They are LEGIT and they are INCREDIBLE.
One more side note--customer service response is insanely fast also. I emailed a question on a SUNDAY EVENING and got an answer.

GREAT, domestically-owned small business I will support again.

Dan-Owner, HiFi Hopes LLC

Great product

I have not used it yet but it seems to a very quality design and construction.

Variable Transformer 20 amp

The transformer worked great for our project so we bought another for the lab. The meter and dial are off a little. Make sure to verify with volt meter.

Voltage Control

Use this to lower the operating voltage of vintage guitar amplifiers they are designed to run between 115-117AC not 120-125VAC great product!

Variable transformer review

Product has worked fine for my purposes but some of the build quality could be better. The two 120v outlets are somewhat loose/sink into the chassis when plugging in power cords but they do seem to have some sort of spring tension to return them. It would be nice if they were more sturdy and I don’t particularly want to take the unit apart to fix this myself. The small output voltage gauge is generally useless. While the numbers around the main dial are easy to read they’re somewhat off relative to the actual output. I could fix that easily by repositioning the dial, but ultimately I use a multimeter to determine the actual output voltage.

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