i designed this simple ignition switch/anti spark circuit that precharges and connects the motor controller to the battery using one switch and a minimum of two relays. there is no timing circuit required and no solid state relays.
this setup use relays that with coils which require 27 volts to actuate (marketed as 36v relays), though you could use a voltage divider on the control relay and limiting resistors on the power delivery relays and use relays with 12v coils, it would be kind of inefficient though.
they are 5 pin SPDT relays.
the minimum number of relays is two, one relay is used as a control relay and it can turn on one or more other relays. depending on how many amps you want to run, i would use one relay for every 10-15 amps. i have one control relay and three power delivery relays on my current setup.
this is for a 36v system. you can buy 48v versions of the same relays which should work for 48/52v setups.
i bought the relays on am@z0n, they are 36v 40a relays. i measured the resistance on the relay coil at 400ohms which is quite high so they will use up to 4 watts of power each (maybe more i need to connect a meter up and measure the amps across the coils still)
i tested the relays and they turn on at 27 volts, im using this to my advantage to reduce inrush current and prevent contact welding.
there is no spark when connecting the battery because there is no direct connection to the capacitors.
i am using a vesc which makes it easy to connect a wire to the positive lead on the controller AFTER the capacitors, but you should be able to do the same on any other controller though, if you open it up.
this is the most basic setup. on my setup i have modified it to use a step down voltage buck converter to power the three power delivery relays at 27.5 volts to reduce their power consumption. i could also put one on the control relay (i believe) but i only had one voltage converter to work with.
it does not require a switch and it does not require a high wattage resistor
i havent had much practice drawing schematics and i still need to learn how to use circuit design software, so all i have is this picture i drew by hand on a whiteboard.
i will add a parts list later.
[url][url][ATTACH type="full" alt="...-D86A46BE2680.jpeg"]302912._xfImport[/ATTACH][/url][/url]
this setup use relays that with coils which require 27 volts to actuate (marketed as 36v relays), though you could use a voltage divider on the control relay and limiting resistors on the power delivery relays and use relays with 12v coils, it would be kind of inefficient though.
they are 5 pin SPDT relays.
the minimum number of relays is two, one relay is used as a control relay and it can turn on one or more other relays. depending on how many amps you want to run, i would use one relay for every 10-15 amps. i have one control relay and three power delivery relays on my current setup.
this is for a 36v system. you can buy 48v versions of the same relays which should work for 48/52v setups.
i bought the relays on am@z0n, they are 36v 40a relays. i measured the resistance on the relay coil at 400ohms which is quite high so they will use up to 4 watts of power each (maybe more i need to connect a meter up and measure the amps across the coils still)
i tested the relays and they turn on at 27 volts, im using this to my advantage to reduce inrush current and prevent contact welding.
there is no spark when connecting the battery because there is no direct connection to the capacitors.
i am using a vesc which makes it easy to connect a wire to the positive lead on the controller AFTER the capacitors, but you should be able to do the same on any other controller though, if you open it up.
this is the most basic setup. on my setup i have modified it to use a step down voltage buck converter to power the three power delivery relays at 27.5 volts to reduce their power consumption. i could also put one on the control relay (i believe) but i only had one voltage converter to work with.
it does not require a switch and it does not require a high wattage resistor
i havent had much practice drawing schematics and i still need to learn how to use circuit design software, so all i have is this picture i drew by hand on a whiteboard.
i will add a parts list later.
[url][url][ATTACH type="full" alt="...-D86A46BE2680.jpeg"]302912._xfImport[/ATTACH][/url][/url]