Skip to content
Read our latest tech news 'Ignition Coils – Troubleshooting Guide'
Read our latest tech news 'Ignition Coils – Troubleshooting Guide'

MOSFET 20 Amp Voltage Rectifier Regulator

Original price $209.63 - Original price $209.63
Original price
$209.63
$209.63 - $209.63
Current price $209.63

The Ultimate Charging Upgrade for Classic British Motorcycles

Upgrade your classic bike’s charging system with the latest in solid-state technology. This heavy-duty MOSFET voltage regulator replaces outdated, hot-running zener diodes and plate rectifiers with a cool, highly efficient solution that preserves your bike's precious power.

Product Description

Upgrade your classic bike’s charging system with the latest in solid-state technology. This heavy-duty MOSFET voltage regulator replaces outdated, hot-running zener diodes and plate rectifiers with a cool, highly efficient solution that preserves your bike's precious power.

While conventional diode regulators waste over 20 watts of power as heat, this modern MOSFET unit runs exceptionally cool—meaning you can safely tuck it away in tight spaces without worrying about overheating or reliability issues.

Key Features & Benefits

  • High-Capacity Power: A generous 20-amp rating comfortably exceeds the demands of standard 10A, 14.5A, and 16A stators.
  • Cool & Compact: Its small footprint (80 x 67 x 20 mm) allows for easy fitting under seats or behind side panels. Because it runs cool, it can be completely hidden from view.
  • Premium Wiring: Equipped with extra-long (60 cm) heavy-gauge wiring housed in dual protective sleeving, giving you total flexibility to route and connect exactly how you want.
  • Peace of Mind: Includes detailed wiring instructions and is backed by a 2-year warranty.

Compatibility

This universal regulator is compatible with any single-phase (2-wire) or three-phase (3-wire) permanent magnet 12-volt alternator up to 20 amps. It is a direct upgrade for common Lucas stators used on Triumph, Norton, BSA, Royal Enfield, Matchless, and more:

  • RM21 (10-amp single phase)
  • RM23 (16-amp single phase)
  • RM24 (14.5-amp three phase)

Dimensions & Mounting

  • Body Size: 80 x 67 x 20 mm
  • Mounting Hole Centres: 64 mm

Installation & Frequently Asked Questions

Polarity: Positive or Negative Earth?

Yes, it works with both. The Tri-Spark MOSFET Regulator features universal polarity. Whether your British classic retains its original positive earth setup or has been converted to a modern negative earth system, this single unit handles it perfectly.

What if I have a 2-Wire (Single-Phase) Stator?

If your bike has a two-wire stator and you notice three stator wires on the regulator, don't worry!

  • The Fix: Simply leave the Yellow wire disconnected.
  • Pro Tip: We recommend trimming the unused yellow wire back and sealing the end with heat-shrink tubing to keep your harness tidy and moisture-proof. The "smart" regulator will automatically manage the charging load perfectly through the remaining two wires.

How do I wire the Red and Black leads?

Wiring doesn't need to be intimidating. For a standard installation, the mapping is straightforward:

  • Red Wire: Connect directly to Earth (Chassis/Ground).
  • Black Wire: Connect to the Brown wire that originally went to your old rectifier.

See it in Action

Watch our Video above, where we bench-test and compare conventional diode voltage regulators against the superior efficiency of this MOSFET unit.

Specifications

VR-0030

  • Size is 80 x 67 x 20 mm.
  • Mounting hole centres 64mm.
  • 20 amp rating
  • 60 cm long wire.

Shipping Taxes and Payments

Shipping 

We generally use Australia post to deliver your order

  • Within Australia - STANDARD post 2-6 business days. (Estimated 2-5 business days for same state delivery and interstate capital cities, except WA and NT.
  • Within Australia - EXPRESS post 1-5 business days. (Estimated 1-2 business days for same state delivery and interstate capital cities, except WA and NT.
  • International - Australia Post STANDARD airmail service. Delivery in 6-17 business days. (Estimated 6-17 business days for metro to metro delivery. Items sent to regional and rural locations may take longer.)
  • International - Australia Post EXPRESS airmail service. Delivery in 5-12 business days. (Estimated 5-12 business days for metro to metro delivery. Items sent to regional and rural locations may take longer.)

For Australia Post's international delivery times and destination guide click here

We provide Australia Post with your mobile phone number and email address, where applicable.  Australia Post will use this information to communicate with you regarding your delivery from us.  This may be in the form of SMS or email notification.  

Postage Calculator

You can calculate the postage in the view cart area.   Click on 'Calculate Shipping' and enter your details.

International Orders -Taxes, Customs and Duty

Orders shipped outside Australia may be subject to customs duties, taxes, or import charges. These costs are set by your local authorities and vary from country to country.

For international orders (excluding the USA):

  • We DO NOT collect customs duties or taxes at checkout.
  • If charges apply, they will be collected by your local customs office or postal service when your order arrives.
  • Please check with your local post office or customs authority to understand what cost may apply.

For USA customers:

  • Any applicable Trump tariffs are already included in the price you pay on our website.
  • In most cases, this means no additional charges are collected on delivery, though local rules and regulations may change.

Payment Options and Advice

We offer a variety of secure payment methods to make your checkout experience easy and convenient.

Accepted Payment Methods

  • All Major Credit Cards – Shop and pay in your own currency with Visa, MasterCard, American Express, and more.

  • PayPal – Available to customers paying in Australian and USA Dollars.

  • Bank Deposit – Available to Australian customers only. Our bank details will be provided on the next page after you select this option at checkout.

  • Shop Pay – A fast and secure checkout option.

  • Google Pay (G Pay) – Quick checkout using your saved Google account details.

Note: If you do not want your payment information saved for future purchases, please remember to untick the box that says ‘Save my information for faster checkout’ and clear your mobile phone number from the box above Pay Now.  Leaving this box ticked and your mobile phone number in the box, may impact saved payment information with other online shops.

Express Checkout Options

For a faster checkout, you can use:

  • Shop Pay
  • PayPal
  • G Pay

If you already have an account with any of these services and your details are up to date, your checkout will be streamlined.

Currency

When using any major credit card, you can shop and pay in your own local currency, making your purchase experience seamless no matter where you are in the world.

If you have any questions about payments or need assistance, feel free to contact us – we’re here to help!

Compare products

{"one"=>"Select 2 or 3 items to compare", "other"=>"{{ count }} of 3 items selected"}

Select first item to compare

Select second item to compare

Select third item to compare

Compare