Flashing leds

Very good, if you wanted to build this circuit and see it running, I would recommend a 1uf capacitor, with the other values you have selected in the circuit, otherwise the Leds would appear to be turned on all the time. To see how a circuit would appear in real time, touch an item, say a led, and touch the Eye on the bottom bar. Then run your finger over the desplayed trend changing the time up towards the 1 second time rate, when the pulses get too close together the display will tend to freeze, don't let this happen, change your components to stop this. The 1 second rate is the rate that illustrates real time. If you are working on a circuit that works faster than real time, you would choose a time base.more suitable for it.