An Inexpensive, Digital Ramp, Programmable Temperature Controller

Abstract

An inexpensive programmable temperature controller, which uses a digitally generated voltage ramp for controlling the temperature‐time relationship, is described. The instrument, in conjunction with a thermoelectrically cooled microscope freezing stage, provides selectable cooling or heating rates from 0.25 to 8°C/min, over a temperature span from −40 to +20°C.