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PROMO CODE: FREESHIP for free economy shipping w/orders $49+
CODE: FREESHIP for free economy shipping w/orders $49+
Professional Variable AC Transformer Collection - 2A to 20A Variacs for Lab and Industrial Use

Variable AC Transformers & Benchtop Variacs

AC-DC PowerShack is a premier supplier of high-precision Variable AC Transformers (Variacs) for university laboratories, industrial testing facilities, and electronics repair centers. Our curated selection ranges from 2 Amp to 20 Amp units, engineered for reliability and precision voltage control.

B2B Support & Bulk Procurement:
• University & Gov POs: We accept official Purchase Orders and offer Net-30 terms upon approval.
• Tax-Exempt Ordering: Seamless processing for schools and non-profit research institutions.
• Volume Discounts: Contact us for custom quotes on classroom sets or large-scale industrial requirements.
• Fast Domestic Shipping: All units are in-stock and ship directly from our Torrance, California warehouse.

Available Configurations:
• Standard Units: 3 Amp, 5 Amp, 15 Amp, and 20 Amp (0–130VAC Output).
• Safety Isolated Models: 2 Amp (0–37VAC) and 10 Amp/15 Amp models with galvanic isolation and Digital LCD Voltmeters.

Filters

Isolated variable transformer SC-2T by PHC Enterprise with 200VA, 2A, and 0–37VAC output showing adjustable dial and terminals
Isolated variable transformer SC-2T by PHC Enterprise, Inc. with 200VA, 2A, and 0–37VAC adjustable output. Save 13% Save %
$75.00
$75.00 - $75.00
$75.00
$65.00
$65.00 - $65.00
$65.00

2A Variable Isolation Transformer (200VA) 0–37VAC with LCD Voltmeter | SC-2T

PHC Enterprise, Inc.
5+ in stock

The SC-2T is a compact 2A (200VA) variable isolation transformer (variac) engineered for safe low-voltage AC testing, electronics repair, education...

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$75.00
$75.00 - $75.00
$75.00
$65.00
$65.00 - $65.00
$65.00
Save 13% Save %
Variable transformer SC-3M by PHC Enterprise, Inc., 300VA, 3A benchtop variac with adjustable 0-130VAC for precise voltage control.
Variable transformer SC-3M by PHC Enterprise, Inc. with 300VA capacity and 0–130VAC adjustable benchtop Variac in close-up view. Save 17% Save %
$59.00
$59.00 - $59.00
$59.00
$49.00
$49.00 - $49.00
$49.00

Variable Transformer 300VA (3 Amp) | 0–130VAC Benchtop Variac - SC-3M

PHC Enterprise, Inc.
5+ in stock

Variable Transformer 300VA (3 Amp) | 0–130VAC Output - SC-3M Product Overview: The SC-3M is a compact, precision-engineered 300VA variable transfor...

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$59.00
$59.00 - $59.00
$59.00
$49.00
$49.00 - $49.00
$49.00
Save 17% Save %
Diagram of PHC Enterprise SC-5M 500VA variable transformer showing specifications and wiring details for benchtop use.
Variable transformer SC-5M by PHC Enterprise, Inc., 500VA, 0–130VAC benchtop variac with adjustable voltage control. Save 18% Save %
$72.00
$72.00 - $72.00
$72.00
$59.00
$59.00 - $59.00
$59.00

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

PHC Enterprise, Inc.
5+ in stock

130VAC Output - SC-5M Product Overview: The SC-5M is a precision-engineered 500VA variable transformer designed for precision AC voltage control. T...

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$72.00
$72.00 - $72.00
$72.00
$59.00
$59.00 - $59.00
$59.00
Save 18% Save %
Variable transformer by PHC Enterprise, Inc. with LCD voltmeter, 0-130VAC output, isolation, and 10A capacity for electrical testing.
Variable transformer SC-10T-2 by PHC Enterprise with LCD voltmeter, 0–130VAC output, 10A (1000W), and isolation features. Save 12% Save %
$225.00
$225.00 - $225.00
$225.00
$199.00
$199.00 - $199.00
$199.00

Variable Isolated Transformer 10A (1000W) 0–130VAC with LCD Voltmeter | SC-10T-2

PHC Enterprise, Inc.
5+ in stock

The SC-10T-2 is a heavy-duty 10A (1000VA) variable AC isolated transformer (variac) engineered for safe workbench testing, electronics repair, and ...

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$225.00
$225.00 - $225.00
$225.00
$199.00
$199.00 - $199.00
$199.00
Save 12% Save %
Rear view of PHC Enterprise SC-15M variable transformer, 15A (1500VA), 0–130VAC benchtop variac with control knob and connection terminals.
Variable transformer SC-15M by PHC Enterprise, Inc. showing a benchtop 15A 1500VA variac with adjustable voltage control.
$120.00 - $120.00
$120.00
$120.00 - $120.00
$120.00

Variable Transformer 15A (1500VA) | 0–130VAC Benchtop Variac - SC-15M

PHC Enterprise, Inc.
5+ in stock

1500VA Heavy-Duty Variable Autotransformer (15 Amp) | SC-15M The SC-15M is a high-performance 1500VA variable autotransformer designed for heavy-du...

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$120.00 - $120.00
$120.00
$120.00 - $120.00
$120.00
Variable transformer SC-20M by PHC Enterprise, Inc., 20A benchtop variac with 0-130VAC adjustment, used for voltage control.
Variable transformer SC-20M by PHC Enterprise, Inc., showing a benchtop 20A 2000VA variac with adjustable voltage knob.
Sold out
$120.00
$120.00 - $120.00
$120.00
$99.00
$99.00 - $99.00
$99.00

Variable Transformer 20A (2000VA) | 0–130VAC Benchtop Variac - SC-20M

PHC Enterprise, Inc.
Out of stock

  High-Capacity Variable Transformer 2000VA (20 Amp) | 0–130VAC - SC-20M 🛑 MODEL DISCONTINUED & SOLD OUT The SC-20M (20A) benchtop variac has b...

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$120.00
$120.00 - $120.00
$120.00
$99.00
$99.00 - $99.00
$99.00
Sold out
Replacement contact brush for PHC Enterprise SC-3M variable transformer, part BRUSH-SC3M, shown in close-up image.
$6.00 - $6.00
$6.00
$6.00 - $6.00
$6.00

Replacement contact brush for SC-3M Variable transformer; Part # BRUSH-SC3M to Replacement Carbon Brush for SC-3M Variable Transformer - BRUSH-SC3M

PHC Enterprise
5+ in stock

Part #: BRUSH-SC3M Replacement contact brush for the SC-3M variable transformer.  

$6.00 - $6.00
$6.00
$6.00 - $6.00
$6.00
Replacement carbon brush for SC-5M variable transformer by PHC Enterprise, showing a small, cylindrical carbon brush with metal contacts.
$6.00 - $6.00
$6.00
$6.00 - $6.00
$6.00

Replacement Carbon Brush for SC-5M Variable Transformer - BRUSH-SC5M

PHC Enterprise
5+ in stock

Part #: BRUSH-SC5M Replacement contact brush for the SC-5M variable transformer.  

$6.00 - $6.00
$6.00
$6.00 - $6.00
$6.00
Replacement carbon brush set for PHC Enterprise SC-10T and SC-20M variable transformers, showing the brush components and contacts.
$9.00 - $9.00
$9.00
$9.00 - $9.00
$9.00

Replacement Carbon Brush for SC-10T & SC-20M Variable Transformers - BRUSH-SC20

PHC Enterprise
5+ in stock

Part #: BRUSH-SC20 Replacement contact brush for the SC-10T, SC10T-2, and SC-20M variable transformer.  Priced as pairs. Priced as pair/set

$9.00 - $9.00
$9.00
$9.00 - $9.00
$9.00
Replacement carbon brush for PHC Enterprise SC-15T variable transformer, shown with multiple brushes for electrical contact.
$15.00 - $15.00
$15.00
$15.00 - $15.00
$15.00

Replacement Carbon Brush for SC-15T Variable Transformer - BRUSH-SC15

PHC Enterprise
5+ in stock

Part #: BRUSH-SC15 Replacement contact brush for the SC-15T variable transformer.  Sold in pairs. Priced as pair/set

$15.00 - $15.00
$15.00
$15.00 - $15.00
$15.00

Let customers speak for us

from 328 reviews
12V AC-AC Power Adapter, 1000mA (1A) Wall Transformer, 2.1mm x 5.5mm Plug | Model AC-121A

12V AC-AC Power Adapter, 1000mA (1A) Wall Transformer, 2.1mm x 5.5mm Plug | Model AC-121A

Samuel Mangum
DC Barrel Plug Adapter to 6.3 x 3.0mm plug from 2.1 x 5.5mm

DC Barrel Plug Adapter to 6.3 x 3.0mm plug from 2.1 x 5.5mm

Robert Chase
Variable Isolated Transformer 10A (1000W) 0–130VAC with LCD Voltmeter | SC-10T-2
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

Dan-Owner, Hifi Hopes Vintage Audio Restoration
AC-AC Power Supply 16V AC @ 1250mA; 2.1 x 5.5mm
Great service and communication

Got my power supply on time and it’s a great deal!

Roma Solomatov
12V 500mA AC-DC Linear Power Supply (2.1mm x 5.5mm) | PV-1250A
Replacement for Morpheus Droptune Pedal

Needed a replacement for a few guitar pedals. This is a perfect replacement for many pedals. Just verify center polarity and amp requirements.

Brandon Pockat
500VA Isolation Transformer 117VAC to 117VAC | ISO-500
Works. Looks good too.

More compact with the toroid transformer.

James Bradshaw
Professional 1000VA Isolation Transformer | 117VAC to 117VAC - ISO-1000
Professional 1000VA Isolation Transformer | 117VAC to 117VAC - ISO-1000

Work as described.

Henry Huynh
AC adapter to my harmonizing pedal

I plugged my new AC adapter to my harmonizing pedal and it worked perfectly. You got one happy customer! Thank you very much.

Sam Striegel
500VA Isolation Transformer 117VAC to 117VAC | ISO-500
Excellent Packing

Unit works exactly as it should. This unit is heavy, it was double boxed along with bubble wrap and fitted inserts. Outstanding!

Brad Gensmer
DC Barrel Plug Adapter, Female 2.1mm x 5.5mm to Male 0.7mm x 2.5mm, 18 AWG | RC-X0725
DC Barrel Plug Adapter to 0.7 x 2.5mm plug from 2.1 x 5.5mm

A fantastic well made product. I am using this plug to power a early 2000 QRP transceiver and it works perfectly

Douglas Rehder
12V 500mA Linear Power Supply 3.5mm Plug | PV-1250C
Great Service

They had a transformer that matched my needs.
Great price and fast response.

Mike Nichols
6ft 2.5mm x 5.5mm DC Power Extension Cable, 20 AWG

We are totally satisfied with this product and the delivery time.

J.M.P.
6V AC-DC Linear Power Supply, 1400mA (1.4A), Negative Center | PV-61A
6V AC-DC Linear Power Supply

Works like a charm for my Grundig 350DL as I lost the original years ago. Thank you AC-DC PowerShack.

RALPH HALL
DC Barrel Plug Adapter to 2.5 x 5.5mm RIGHT ANGLE plug from 2.1 x 5.5mm

Great product

Rod Espinoza
Universal AC-DC Power Adapter (3V-12V, 600mA) Multi-Plug Regulated Switching Supply (7 Tips) | PHC-600K
Works with my CASIO SK-1 KeyBoard

600mA 7.5VDC Tip (-)

Mark Klein