MIREXAL SOLAR ESA9362 QUARTZ 1977
A "Solar" by a private label Mirexal from 1977. This akward watch can be found with various brands on the dial and is a smart combination of a robust mechanical movement with quartz module with an additional solar panel. The ESA9362 has been discussed earlier so let's focus on the solar module. It is very unlikely a factory combination created inhouse by ESA as the Swiss conglomerate usually changed the calibre markings with even slightest movement modifications. The concept is very simple and smart and might have been built by an external company such as Mondaine which cooperated with Mirexal.
A solar panel is fitted to the dial with one end of the panel soldered to the metal. The dial feet connect the panel circuit with the base of the movement which has positive polarity. The other end of the panel is soldered onto a substrate board insulated from the dial and movement. The negative polarity of the battery is connected with an insulated red copper wire which goes through the movement and connects directly to the substrate under the dial. This closes the circuit allowing the solar panel to gather and forward energy to an accu cell. The caseback and manual suggests using Mallory 10SL18 or equivalent but the movement will also run on a standard 389 battery although it should not be charged.
Keywords: mirexal solar, solar quartz
Market value: 50-150$ (version, condition)
