The temperature range of this circuit is different from the previous one, while maintaining the same configuration. The circuit is from a Radio Electronics from June 1985.
We found this circuit in a technical documentation on the National Semiconductor LM3909. The...
The LEDs act as diodes, so if good they will show the same characteristic curve. Arrangment shown...
This circuit is from an old English publication from 1968. We can implement it with TIP32...