http://falstad.com/circuit/circuitjs.html?cct=$+1+0.000005+9.78399845368213+50+5+50%0AR+192+80+192+48+0+0+40+5+0+0+0.5%0Ar+192+80+192+128+0+4700%0At+192+128+288+128+0+1+0+0+100%0Ac+352+80+352+112+0+0.00009999999999999999+0.001%0Al+352+144+352+176+0+0.01+0%0Aw+192+176+192+128+0%0Aw+288+144+288+176+1%0Aw+288+176+352+176+0%0Aw+352+80+288+80+1%0Aw+288+80+288+112+0%0Aw+288+80+192+80+0%0At+160+192+192+192+0+1+0+0+100%0Ag+192+208+192+224+0%0Ar+160+192+96+192+0+4700%0AL+96+192+80+192+0+0+false+3.3+0%0Ad+288+176+192+176+1+0.805904783%0Ar+352+112+352+144+0+203%0Aw+400+176+352+176+0%0Aw+352+112+400+112+0%0Ap+400+112+400+176+1+0%0Ao+4+64+0+4353+80+0.00009765625+0+2+4+3%0Ao+19+64+0+4354+0.0000762939453125+0.1+1+1%0A this is such a fascinating little circuit. It converts a continuous digital signal into positive or negative current pulses through the resistor/inductor whenever it changes, meaning you can use it to drive a single-coil latching relay with a simple digital output. Also I really hope mastodon shortens that link.