Good Evening all. I just started a instructor job for a HVAC/R Technical school teaching ELE-101(Entro to Electricity) and ELE-102(Digital Control Circuirts) and need some input for a good digital control book. ELE101 covers OHM's law and Series/Parallell circuits and gets into A/C formulas and all. I need a good text book for the DCC class. Something that covers basic controls like P-I and P-I-D loops, sensors and a I/O programmer. Another instructor goes into PLC's but his class builds off my two. Any help would be greatly appriciated. Thank you in advance.