Block diagrams of two high-stability scanning time-interval generators that can be used to automate tuning and testing of relative-time actuation channels in particle detectors are described. The first generator has the following performance characteristics: an operation range of 0–255 ns, a scan step of 1 ns, and a maximum error of ±0.5 ns. This error remains unchanged within the time of a single scan. The second generator has two operating modes. In the first one (the scan mode), it has an operation range of 50–3000 ns and a scan step of 50 ns. In the second mode, with fixed duration of time intervals, it has an operation range of 50–12 750 ns that can be changed with an increment of 50 ns. The relative error in the duration of the generated interval is 10−5 s.