GTO Transformer, 18 Volt/40VA
The RB570 is a replacement low-voltage AC transformer used to keep the battery charged on select GTO, Linear PRO and Mighty Mule automatic gate openers. These battery-powered gate openers do not run directly from the plug-in transformer. Instead, the transformer feeds the charging circuit, which maintains the battery so the operator can run reliably between cycles.
The transformer rating is important. RB570 is commonly listed as an 18 volt, 40VA transformer for UL-rated systems. Installing the wrong voltage or undersized transformer can lead to poor charging, blown fuses, control board damage, or a battery that never fully recovers. A dead gate after a few cycles is not always caused by the transformer; batteries, wire runs, charging circuits and accessories must also be checked.
This part is often replaced when the original plug-in transformer is missing, damaged by weather, burned out, or no longer producing the correct low-voltage output. It is also commonly ordered during service on older Mighty Mule and GTO systems after confirming the unit is a post-UL model that uses this transformer.
Compatible With
The RB570 transformer is commonly used with selected UL-rated GTO, Linear PRO and Mighty Mule automatic gate opener systems, including:
- Mighty Mule MM350, MM500, MM502 and MM600 series gate openers
- Older Mighty Mule FM350, FM352, FM500, FM502 and FM600 series where the manual calls for an 18V 40VA transformer
- GTO / Linear PRO SW2000, SW3000, SW4000 and SW4200XL swing gate openers where specified
- GTO / Linear PRO SL1000 and SL2000 slide gate openers where specified
- GTO / Linear PRO GPX-SL25 slide gate opener charging system
- RB709U receiver garage door applications referenced with this transformer in some older documentation
- Not for every pre-UL, solar-only, AC-powered, or different-voltage gate operator
Features & Specifications
| Manufacturer | GTO / Linear PRO / Mighty Mule family |
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| Product Type | Plug-in transformer |
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| Part Number | RB570 |
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| Application | Battery charging power supply for select gate openers |
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| Voltage | 18 VAC output |
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| Power Rating | 40VA |
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| Compatible Operator Type | Select UL-rated battery-operated swing and slide gate openers |
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| Notes | Used to maintain battery charge through the operator charging circuit |
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Also Known As / Related Part Numbers
- RB570
- LIN-RB570
- GTO RB570
- Linear RB570
- Mighty Mule RB570
- 18V 40VA transformer
- 18 volt 40VA transformer
- replacement gate opener transformer
Technician Note
Before replacing the transformer, test the battery and inspect the low-voltage wire from the transformer to the control box. Long wire runs, corroded splices and damaged cable can mimic a failed transformer.
Before Ordering Checklist
- Confirm the operator uses an 18 VAC 40VA transformer.
- Verify the opener is a compatible UL-rated Mighty Mule, GTO or Linear PRO model.
- Check the battery condition and charging fuse before ordering.
- Inspect low-voltage wire for cuts, corrosion or undersized cable.
- Do not connect this transformer to high-voltage operator terminals or unrelated equipment.
Important Ordering Warnings
Older pre-UL models and some different-voltage systems may not use RB570. Transformer parts are often non-returnable once installed, so confirm the model and rating first.
Professional Advisory
Low-voltage transformer replacement is simple in many installations, but damaged wiring, repeated fuse failures, water intrusion or control board charging problems should be handled by a qualified technician.
Product Questions & Answers
What is the RB570 transformer used for?
The RB570 supplies 18 VAC, 40VA low-voltage power to the charging circuit on select GTO, Linear PRO and Mighty Mule battery-operated gate openers.
Does the transformer run the gate directly?
No. On these systems the battery runs the operator, and the transformer maintains the battery charge through the control board charging circuit.
Which models commonly use RB570?
It is commonly listed for many UL-rated Mighty Mule and GTO/Linear models, including MM350, MM500, MM502, MM600, SW2000, SW3000, SW4000, SW4200XL, SL1000, SL2000 and GPX-SL25 where specified.
Can a bad battery make the transformer look faulty?
Yes. A weak or shorted battery, damaged wire, blown fuse or failed charging circuit can make the system appear to have a transformer problem.
Is RB570 for every Mighty Mule gate opener?
No. Confirm the operator model, UL generation and required transformer rating before ordering.
