Summary

The initial state of an SR (set-reset) latch is, in principle, indeterminate. The circuit is a SR (set-reset) latch with a power-on reset (POR), so that the initial state after power-on is determined.

Circuit

Schematic

Transistor T3 is off while capacitor C1 charges through resistor R5.

Consequently, the voltage at the collector of T1_L is high, transistor T1_R is on, the voltage at the collector of T1_R is low and transistor T1_L is off.

Transistors T1_L and T1_R remain in those states, even when capacitor C1 has charged sufficiently such that the base current of transistor T3 turns it on.

Stripboard

The stripboard size is 9 tracks of 25 holes.