Another simple interval-programming circuit.

L et al. built a new timing circuit for lab boxes. It sets fixed or variable intervals without fancy parts.

The circuit uses only switches and relays. No R-C networks. No rectifiers. It still gives full control.

The setup worked. It sent pulses at set times. It kept the same power as older, fussier circuits.

Labs could copy the plan with cheap parts. The board was smaller and easier to fix.

Hagopian (2020) and Frazier et al. (2018) came later. They give new rules for single-case designs, not new circuits. Their papers extend the same spirit: better control of timing and data.

Downing et al. (1976) also built a tool, but for teaching, not timing. Both papers share the aim of tight behavioral control.

None of these papers clash. The 1962 note gives the hardware base. The newer ones give design checklists and rating tools.

If you run custom lab setups, this old circuit still saves money and space. You can build it in an afternoon and get reliable interval pulses for animal or human work. Pair it with modern design checks from Hagopian or W et al. to keep your whole experiment clean.