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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 Transformer

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.

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SC-2T 2 Amp Isolated Variac with LCD Digital Display for Precision Lab Testing
SC-2T 2 Amp Isolated Variable Transformer 0-37VAC for Safe Lab and Electronics Testing Save 13% Save %
$75.00
$75.00 - $75.00
$75.00
$65.00
$65.00 - $65.00
$65.00

Isolated Variable Transformer 200VA (2 Amp) | 0–37VAC Output - SC-2T

PHC Enterprise, Inc.
5+ in stock

Isolated Variable Transformer 200VA (2 Amp) | 0–37VAC Output - SC-2T Product Overview: The SC-2T is a professional-grade 200VA isolated variable tr...

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$75.00
$75.00 - $75.00
$75.00
$65.00
$65.00 - $65.00
$65.00
Save 13% Save %
SC-3M Variable Transformer Technical Drawing and Specifications Sheet
SC-3M 300VA Variable Transformer 0-130VAC Benchtop Variac for Research Labs 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 %
SC-5M Variable Transformer Technical Specifications and Wiring Diagram
SC-5M 500VA Variable Transformer 0-130VAC Benchtop Variac for Labs 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 Variac - 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 %
SC-20M Technical Specifications 2000VA 20A Variable Transformer 0-130VAC
SC-20M 20 Amp High-Capacity Variable Transformer 2000VA for Industrial Testing Save 18% Save %
$120.00
$120.00 - $120.00
$120.00
$99.00
$99.00 - $99.00
$99.00

High-Capacity Variable Transformer 2000VA (20 Amp) | 0–130VAC Output - SC-20M

PHC Enterprise, Inc.
Only 3 left!

High-Capacity Variable Transformer 2000VA (20 Amp) | 0–130VAC - SC-20M Product Overview: The SC-20M is a heavy-duty 2000VA variable transformer bui...

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$120.00
$120.00 - $120.00
$120.00
$99.00
$99.00 - $99.00
$99.00
Save 18% Save %
SC-15M Variable Transformer 15 Amp Dual AC Outlets and Grounded Power System
SC-15M 15 Amp Variable Transformer 1500VA with LCD Digital Voltmeter
$120.00 - $120.00
$120.00
$120.00 - $120.00
$120.00

15A Variable Transformer | 1500VA Benchtop Autotransformer | 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
Close-up of technical specifications label for SC-10T-2 showing 1000VA power rating and Galvanic Isolation details
0 Amp Isolated Variable Transformer with LCD Volt Meter and Dual AC Outlets, 1000VA Variac Model SC-10T-2
Save 12% Save %
$225.00
$225.00 - $225.00
$225.00
$199.00
$199.00 - $199.00
$199.00

Variable Transformer 10 Amp (1000 Watts); 0~130VAC Output ISOLATION & LCD Volt Meter

PHC Enterprise, Inc.
5+ in stock

Why Choose the SC-10T-2? True Galvanic Isolation for Safety: Essential for safely servicing "hot chassis" vintage electronics and radio equipme...

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$225.00
$225.00 - $225.00
$225.00
$199.00
$199.00 - $199.00
$199.00
Save 12% Save %
Replacement contact brush for SC-10T/SC-20M Variable transformer; Part # BRUSH-SC20 - AC-DC PowerShack
$9.00 - $9.00
$9.00
$9.00 - $9.00
$9.00

Replacement contact brush for SC-10T/SC-20M Variable transformer; Part # 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 contact brush for SC-15T Variable transformer; Part # BRUSH-SC15 - AC-DC PowerShack
$15.00 - $15.00
$15.00
$15.00 - $15.00
$15.00

Replacement contact brush for SC-15T Variable transformer; Part # 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
Copy of Replacement contact brush for SC-5M Variable transformer; Part # BRUSH-SC5M - AC-DC PowerShack
$6.00 - $6.00
$6.00
$6.00 - $6.00
$6.00

Replacement contact brush for SC-5M Variable transformer; Part # 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
Copy of Copy of Replacement contact brush for SC-3M Variable transformer; Part # BRUSH-SC3M - AC-DC PowerShack
$6.00 - $6.00
$6.00
$6.00 - $6.00
$6.00

Replacement contact brush for SC-3M Variable transformer; Part # 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

Let customers speak for us

from 303 reviews
AC-AC Power Supply 24V AC @ 1750mA; 2.1 x 5.5mm
All Good

Great item inventory, very swift shipping/delivery, and the power supply is what I ordered and functions flawlessly. Thanks again!

deno canellos
AC-AC Power Supply 24V AC @ 1750mA; 2.1 x 5.5mm
5 AMP GDC SLOW BLOW FUSE 5x20mm 5-pack; Part # GTE-5A-5

5 AMP GDC SLOW BLOW FUSE 5x20mm 5-pack; Part # GTE-5A-5

Karpis Maksudian
5 AMP GDC SLOW BLOW FUSE 5x20mm 5-pack; Part # GTE-5A-5
Professional 1000VA Isolation Transformer | 117VAC to 117VAC - ISO-1000

Isolated ok

John E Oden
Professional 1000VA Isolation Transformer | 117VAC to 117VAC - ISO-1000
DC Barrel Plug Adapter to 3.4mm x 5.0mm with center pin (1.0mm) plug from 2.1 x 5.5mm
Works as intended!

Works perfect, just what i needed. Thank you😀

Erik B. Hamm
DC Barrel Plug Adapter to 3.4mm x 5.0mm with center pin (1.0mm) plug from 2.1 x 5.5mm
12VCT 12V, 6V Transformer 0-6V-12V CT @ 1A 117VAC to 12VAC or 6VAC
Awesome

Awesome

braulio coyoy
12VCT 12V, 6V Transformer 0-6V-12V CT @ 1A 117VAC to 12VAC or 6VAC
DC Barrel Plug Adapter to 2.1 x 5.5mm plug from 2.1 x 5.5mm; REVERSES the POLARITY
Obscure part, quick delivery

I was having trouble finding exactly what I needed, but you had it and it was in my mailbox within the week. Thank you for the quick service.

Richard E.
DC Barrel Plug Adapter to 2.1 x 5.5mm plug from 2.1 x 5.5mm; REVERSES the POLARITY
AC-DC Linear Power Supply 7.5V DC @ 1000mA; 2.1 x 5.5mm NEGATIVE center polarity

AC-DC Linear Power Supply 7.5V DC @ 1000mA; 2.1 x 5.5mm NEGATIVE center polarity

Matthew Farmer
AC-DC Linear Power Supply 7.5V DC @ 1000mA; 2.1 x 5.5mm NEGATIVE center polarity
AC-DC Switching Regulated Power Supply 6.5V DC @ 500mA; 1.7 x 4.0mm Positive center polarity
Works great, arrived quickly

A 6.5VDC, 500mA with a 1.7x4.0mm isn't a common animal, but got this at AC-DC Powershack and it works great. Got here fairly quickly too.

Brian Annis
AC-DC Switching Regulated Power Supply 6.5V DC @ 500mA; 1.7 x 4.0mm Positive center polarity
Professional 500VA Isolation Transformer | 117VAC to 117VAC - ISO-500
PHC 500VA Isolation Transformer, 117VAC

A true isolation transformer. Simplistic and effective. Outstanding.

Jon Diemert
Professional 500VA Isolation Transformer | 117VAC to 117VAC - ISO-500
Variable Transformer 300VA (3 Amp) | 0–130VAC Benchtop Variac - SC-3M
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!

Mike DiMasi
Variable Transformer 300VA (3 Amp) | 0–130VAC Benchtop Variac - SC-3M
25.0 AMP GMA FAST BLOW FUSE 5x20mm 5-Pack; Part # GMA-25A-5

I order .25 fuse not 25 amp fuse

Frank Jay Hoffman
25.0 AMP GMA FAST BLOW FUSE 5x20mm 5-Pack; Part # GMA-25A-5
DC Barrel Plug Adapter to 2.1 x 5.5mm plug from 2.5 x 5.5mm

Tight and perfect

Randy
DC Barrel Plug Adapter to 2.1 x 5.5mm plug from 2.5 x 5.5mm
Professional 500VA Isolation Transformer | 117VAC to 117VAC - ISO-500
500 VA Isolation Transformer

Item packaged well, shipping was fine, working as expected. Happy with purchase.

Michael Perry
Professional 500VA Isolation Transformer | 117VAC to 117VAC - ISO-500
12V AC-AC Power Adapter, 1000mA (1A) Wall Transformer, 2.1mm x 5.5mm Plug, AC12V Linear Power Supply

AC-AC Power Supply 12V AC @ 1000mA; 2.1 x 5.5mm

Saksiri Tanphaichitr
12V AC-AC Power Adapter, 1000mA (1A) Wall Transformer, 2.1mm x 5.5mm Plug, AC12V Linear Power Supply
12V AC-AC Power Adapter, 1000mA (1A) Wall Transformer, 2.1mm x 5.5mm Plug, AC12V Linear Power Supply
Excellent product!

Thanks to this AC/AC adapter, this Zoom RFX-2000 unit was brought back to life.

Thank you ACDC PowerShack, excellent service.

Julio H.
12V AC-AC Power Adapter, 1000mA (1A) Wall Transformer, 2.1mm x 5.5mm Plug, AC12V Linear Power Supply