American Optical 365T Microscope Illuminator Transformer 115V 5.5-6.5V No Bulb

American Optical 365T Microscope Illuminator Transformer 115V 5.5-6.5V No Bulb

The American Optical 365T is a benchtop microscope light source consisting of a step-down transformer and a separate lamp head assembly. The transformer takes standard 115V AC mains power and steps it down to a 5.5–6.5V output to drive a low-voltage microscope lamp. A front-panel rotary switch with Off, Lo, Med, and Hi positions controls lamp brightness. No bulb is included with this unit. The illuminated photos in the listing show a separate functioning unit used for demonstration purposes only.

Specifications & What's Included

• Manufacturer: American Optical Corporation, Buffalo, NY
• Model: 365T
• Component type: Microscope illuminator transformer
• Primary voltage: 115V AC
• Frequency: 60 Hz
• Secondary voltage: 5.5 to 6.5V
• Power rating: 23 VA
• Brightness control: Rotary switch — Off / Lo / Med / Hi
• Pilot indicator lamp socket on front panel
• Lamp head: finned cylindrical housing with output tube/snout and condenser lens
• Power cord with standard US 2-prong plug included
• UL Listed (File 488.6)
• Made in the USA
• Bulb not included — lamp head is sold without a bulb

Applications

The American Optical 365T is designed for use with American Optical and compatible microscopes that require an external low-voltage illuminator. Units like this were standard equipment on American Optical compound and stereo microscopes produced from the 1960s through the 1980s, a period when AO Corporation was one of the leading American microscope manufacturers. The separate transformer-and-lamp-head configuration was common in that era, allowing users to replace bulbs independently and to control light intensity through a simple multi-step switch. These illuminators are still sought after today by users maintaining vintage AO microscopes in labs, educational settings, and biological research environments, as well as by collectors restoring period microscope setups. Replacement bulbs compatible with the 5.5–6.5V output are available from microscope supply vendors.