Single push button relay with reset

Question

I have an automotive application where I would need a 12V relay/circuit that can be toggled with single button between on/off. But it should reset itself back to when input voltage drops to zero.

I found this: https://www.the12volt.com/installbay/uploads/E33_Latching_Relay_2.gif but it seems to require two buttons.

Edit: I am controlling 12V 6A max.

Edit 2: I found promising looking one button two relay circuit: http://www.homofaciens.de/technics-base-circuits-relay_en.htm and there figures 32-41. Any comments on that?

• user80875: You can not get that function with one button and one ordinary relay.
• jonk: Also, electronics-lab.com/project/toggle-on-off-switch
• Jasen Слава Україні: @jonk, 555 is not really suited to the harsh conditions automotive electrics are exposed to. it only takes 18V to kill them. but other than that it's a good circuit. and probably OK if you're not worried about it failing unexpectedly. MTBF could be 10 years - not good if you sell thousands and hundreds fail in the first year, but possibly acceptable if it is for your own use.
• Transistor: The link of your edit 2 might work but it doesn't satisfy your requirement of only one relay. A flip-flop circuit with one relay may be simpler.
• Petteri H: Ok, the requirement of a single component is not a must.

Answer 1

if you're not averse to using speciality relays like ratchet (alternate acting) and delay you can do it this way:

schematic

^{simulate this circuit – Schematic created using CircuitLab}

or this way:

schematic

^{simulate this circuit}

Answer 2

I ended up using with one button and two relays using the T flip-flop circuit from http://www.homofaciens.de/technics-base-circuits-relay_en.htm. Seems to work fine: https://www.youtube.com/watch?v=EP8Gv7XFv00