as title really

im getting very annoyed with these jet washs where the reels is coiled up and it just isnt long enough, so ive been looking into making my own, plus it will come in handy cleaning the drive and the decking in the garden

so far i can get a pump and an electric motor, hoses etc arnt a problem, but what im struggling is a control unit

i dont want the motor on all the time, so i need a control box so it turns it on when the trigger is pressed but carnt find anything on the net of what i need or how it would be wired up

i was thinking of just using a scrap jet wash circuits to power the motor but unsure if they have a transformer that takes teh voltage down where i need constant 240v supply

any ideas?

what i want to make is something like this