Another use of the thyratron was in relaxation oscillators. The term "thyristor" was derived from a combination of "thyratron" and "transistor". This means that conduction in a thyratron is dominated by plasma conductivity. This theory was later instrumental in the development of the thyratron and the Geiger-Mueller tube. It is from a combination of "thyratron" and "transistor" that the term "thyristor" is derived. Other examples include the thyratron, krytron, sprytron, and ignitron tubes. The first one is the earliest of its kind is the thyratron oscillator. The most widely used type of tube was the thyratron. Thyratron dimmers were manufactured under license from Strand Electric of England. Thyratron relaxation oscillators were used in power inverters and oscilloscope sweep circuits. The "885" is a small thyratron tube, using argon gas. At the consumer ends the thyratron converts the DC into the AC. The counter used gas-filled Thyratron tubes which are bi-stable devices. In an automotive application, the thyratron CD ignition would fail in either weeks or months. The thyratron is a special-purpose tube filled with low-pressure gas or mercury vapor.