This circuit was found in old American documentation. The operational amplifiers are from the period, but modern equivalents can be used.
The integrated circuit of this 80's project is not common today. This is the HA2530 which must be...
This circuit is from a 1992 PE Hobbyst Handbook. The circuit fires an old electronic flash using an...
This complementary transistor stage was found in a 1968 publication. The transistors are germanium types and...