Tech Talk

The Electroplater’s Guide to Power Supplies (Rectifiers): Purpose, Function, Options & When to Use What

 An Educational Guide for Surface Finishing Professionals

 By RHL Associates

Power supplies—often called rectifiers—are the heartbeat of any electroplating line. They convert the alternating current (AC) from your facility into tightly controlled direct current (DC) that drives metal ions out of solution and onto parts. Get the rectifier wrong and even great chemistry, agitation, and fixturing won’t save yield. Get it right and you unlock faster cycles, tighter distribution, and predictable thickness—shift after shift.

Below is a practical overview for surface finishers evaluating new or replacement units, with examples from leading suppliers: Dynatronix, Novak, Aldonex, KraftPowercon, and American Plating Power.



What a plating rectifier does (and why it matters)



• Rectification & regulation – Converts AC to DC and regulates voltage/current so deposition stays stable and repeatable. Poorly regulated output or excessive ripple shows up as burning, nodules, roughness, or poor throwing power.
• Waveform shaping – Beyond steady DC, many units can deliver pulse and periodic pulse reverse (PPR). Pulse/PPR can reduce stress, refine grain, improve brightness, and dramatically improve throwing power on complex geometries and high-aspect-ratio features (e.g., PCB vias).
• Process integration – Modern rectifiers offer remote control/monitoring, ramp and dwell recipes, data logging, and interlocks to keep current in sync with hoists, barrels, and chemistry limits. (See vendor feature sets below.)

The two main rectifier topologies

• SCR/Thyristor (phase-controlled)
• Strengths: Rugged, proven, excellent for very high currents; generally easier to service in harsh environments.
• Trade-offs: Larger, heavier, lower efficiency and power factor than top-tier switch-mode at typical plating voltages; can have higher output ripple.
• Typical uses: Hard chrome, high-amp copper or nickel, electroforming, and big anodize tanks where brute current and durability rule.
• Switch-Mode (IGBT/SMPS)
• Strengths: Compact footprint, high efficiency (often ~90% at 10–12 VDC), excellent dynamic response, low ripple, fine control for delicate deposits.
• Trade-offs: Smaller high-frequency components can be more sensitive to heat/mist if not protected; good cooling and enclosure design matter.
• Typical uses: Precious metals, PCB/semiconductor features, pulse/pulse-reverse processes, lines where space/energy savings count.

• Cooling choices (air vs. water vs. oil) hinge on amperage density, ambient conditions, and enclosure location. High-power SMPS units are frequently water-cooled for reliability and size; air-cooled fits lighter duty and clean rooms better.

Vendor landscape & notable options



Dynatronix (by Process Technology)

• Focus: DC, high-frequency pulse, and pulse-reverse rectifiers (bench to production).
• Examples: MicroStar DPR/DuP series (air-cooled, benchtop and production) with DC, HFP up to kHz, and pulse reverse options—popular for general metal finishing and R&D.
• Best for: Shops introducing pulse chemistry control, fine-grain nickel, precious metals, or when you need flexible waveform recipes without overbuilding.

Novak

• Focus: Compact switch-mode rectifiers purpose-built for electrochemical processes; DCe (standard), PPe (pulse), REVe (reverse), and multi-channel variants.
• Range: ~10–500 A class units in multiple voltages (7–48 V), single- or three-phase inputs; fast delivery cited by distributors.
• Best for: Small to mid-current plating, labs, selective plating stations, precious metals, and applications needing agile control in a small footprint.

Aldonex

• Focus: Wide portfolio of AC/DC rectifiers for electroplating and related processes; custom builds available.
• Range: From ~100 A benchtop up to 100 kA / 400 V class systems; air- and water-cooled; analog or digital controls.
• Best for: Heavy-duty lines (chrome, high-amp copper/nickel, anodize) where robustness and serviceability are paramount and customization is helpful.

KraftPowercon

• Focus: Modular SMPS rectifiers (FlexKraft) with air- or water-cooling (CoolKraft), plus ModuPulse for periodic pulse reverse (PPR), especially in PCB and precious metals.
• Range: Scalable modules for growth, high-current products for plating/electrowinning; designed for uptime and serviceability.
• Best for: Modernization projects prioritizing efficiency, footprint, and pulse/PPR performance—PCB copper, gold, silver; also chrome/anodize with water-cooled packages.

American Plating Power (APP)

• Focus: Broadest portfolio—SCR/thyristor and switch-mode, including PPR systems; built for 24/7 operation in harsh environments.
• Range: From compact SMPS to multi-kA industrial rectifiers; widely stocked in North America with strong service network.
• Best for: Multi-line facilities that want one vendor to cover everything from delicate gold to 3,000 A chrome.

Matching rectifier features to applications

Buying checklist (what to specify)



1. Amps & volts at the work – Size to your worst-case load (largest surface area, lowest conductivity bath, coldest day).
2. Waveform – DC only, pulse, or PPR (periodic reverse). If PPR is critical (PCB/µ-features), shortlist Dynatronix pulse units, KraftPowercon ModuPulse, and APP PPR solutions.
3. Ripple – Specify maximum ripple at nominal load (precious metals often need the lowest).
4. Cooling – Air vs. water-cooled (consider ambient heat/mist, enclosure location, service access). KraftPowercon CoolKraft is a purpose-built option.
5. Controls & connectivity – Analog 0–10 V or 4–20 mA, digital (Ethernet/fieldbus), ramp/dwell recipes, data logging, and alarms.
6. Efficiency & PF – Impacts energy cost and heat load; SMPS typically leads here.
7. Environment & service – Mist, heat, and duty cycle kill electronics; prioritize enclosure rating, coatings, and local service/support (a strong suit for Aldonex and APP in North America).

Quick vendor-at-a-glance

• Dynatronix (Process Technology): Pulse and pulse-reverse specialists from lab to production; benchtop to multi-kW.
• Novak: Compact SMPS with DCe/PPe/REVe families; broad low- to mid-amp options and fast availability.
• Aldonex: Custom AC/DC rectifiers up to 100 kA/400 V, air or water cooled; rugged builds for heavy plating.
• KraftPowercon: Modular FlexKraft SMPS (air/water, CoolKraft), plus ModuPulse PPR for PCB/precious metals.
• American Plating Power: Full line of SCR and SMPS (incl. PPR), designed for 24/7 industrial duty and supported widely in NA.

Putting it together

• If you’re scaling high-current chrome or copper, start with SCR or water-cooled SMPS from Aldonex or APP, sized with headroom for cold-bath days and worst-case racks.
• For precision work (precious metals, fine features), shortlist SMPS with tight ripple and waveform control—Dynatronix pulse units, Novak DCe/PPe/REVe, or KraftPowercon FlexKraft/ModuPulse.
• For PCB copper plating and via fill, look specifically at PPR capability (e.g., KraftPowercon ModuPulse)—it’s a proven lever for distribution and aspect ratio challenges.