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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.

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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...

View full details
$120.00
$120.00 - $120.00
$120.00
$99.00
$99.00 - $99.00
$99.00
Sold out
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 308 reviews
Universal AC-DC Power Adapter (3V-12V, 600mA) - PHC-600K | Multi-Plug Regulated Switching Supply (7 Tips)
Works with my CASIO SK-1 KeyBoard

600mA 7.5VDC Tip (-)

Mark Klein
Universal AC-DC Power Adapter (3V-12V, 600mA) - PHC-600K | Multi-Plug Regulated Switching Supply (7 Tips)
24VCT 24V, 12V Transformer 0-12V-24 CT @ 2A 117VAC to 24VAC or 12VAC
Fixed the Control box

Old transformer went bad after 30 years in service. Part was able to be worked into a tight space and box is working again. Thanks!!

Mikkel Halverson
24VCT 24V, 12V Transformer 0-12V-24 CT @ 2A 117VAC to 24VAC or 12VAC
HDCX6T 6ft 2.1mm x 5.5mm DC Plug Extension Cable, 18 AWG
Just what I needed

As advertised, 18 gauge extension cables. Arrived promptly.

Ronald Simmer
HDCX6T 6ft 2.1mm x 5.5mm DC Plug Extension Cable, 18 AWG
Adjustable DC Regulated Switching Power Supply (Black) 3-15VDC 4A | APS-415
Damn good machine

Easy pleasant transaction, great quality and great value. This machine will be used for a power supply for a homemade electrolysis tank. Don't be afraid to purchase from this company.

Donald Matthies
Adjustable DC Regulated Switching Power Supply (Black) 3-15VDC 4A | APS-415
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