This circuit was found in a 73 magazine for radio amateurs of the 90s. The circuit uses two types of indicators, the diodes are for general use. The power supply is 5 V.
This circuit was found in old English documentation. The sensor is a 1M NTC. The circuit has...
This circuit is from an English magazine of 1974, but can still be assembled with the replacement of...
In the figure we have a small general-purpose amplifier with the LM386 integrated circuit and...