# Why there is a voltage drop while connect multiple 12 V or 24 V solenoid valve with a 24 V DC adapter

I am doing a water plant project. I need to control multiple solenoid valves with my micro controller circuit using relays. When I connect more than 4 solenoid valves (12 V) with a 15 V adapter it will cause a voltage drop and the solenoid valves are not working.

Questions:

1. Why does this happen and how can I fix this problem?
2. How can I connect multiple solenoid valves (ex:64 solenoid valve) with a micro controller using relays?
• How much current can your 15 volt adapter provide? How much current do your individual solenoids take? Do the math. – Andy aka Oct 9 '18 at 11:33
• my adapter is 15v 1amp adapter, it works for 4 solenoid valve. but it not working on more than 4 valve – Natesh Oct 9 '18 at 11:59
• And............... – Andy aka Oct 9 '18 at 12:04
• each solenoid valve takes 12v 500mA current, – Natesh Oct 9 '18 at 12:09
• You figure out the maximum number that will be on simultaneously, total the required current, multiply by a safety factor and buy a power supply that meets or exceeds that specification. – Transistor Oct 9 '18 at 12:53