I have a DC power source which can provide up to 5V, 50mA (LabJack maximum output current, voltage bus-powered) and I want to power my relay (SDT-S-105LMR2,000) with 5V, 100mA. I have an option to use NPN transistor with a DC current gain of approximately 2, but the 0.7V voltage drop is not that nice.
First question - Is the circuit logic correct (more attention on the added current booster)?
Second question - Because I am building 16 channel relay board, is there more convenient option for boosting the current for each of the relay (preferably less components)?
Third question - Will the LabJack supplied power will be a good enough source for 16 relays (working at different times)?