[Miss Ori, Manager]
What is the difference between sink and source logic?
[Mr Vex, Staff]
Mr. Vex:I have received an inquiry from a customer that they wanted to use brushless motors on machines to be imported overseas and source logic types are preferable for users abroad. While i am talking with the customer, terms like "sink" and "source" came up and i couldn't quite see the picture. Maybe i heard him wrong? He could have been asking if it was okay to drink the sauce?
Miss Ori: Nice one! I see that you are getting comfortable with your job to come up with such jokes. By the way, was it about I/O circuits?
Mr. Vex: I think so. We were discussing about PLC(programmable logic controller)
Miss Ori: So do you know the difference between sink and source logic types?
Mr. Vex: Don't know. Please share with me
Miss Ori: In reality, the sink and source logic uses different control output devices.
There are two major types, and their wiring is different.
[Figure 1] Sink logic- NPN transistor
[Figure 2] Source logic - PNP transistor
Mr. Vex: So , the connection needs to be changed according to each transistor, right?
Miss. Ori: Not only the connection, but there is also a difference with regards to safely too. If by any chance something happen to customer's device and causes an I/O signal line earth leakage or short circuit of the Gnd(0V) line, it would be dangerous, would't it. [Figure 3]
However if the source logic was used, the input circuit is not directly connected to the positive power side(Vcc), therefore earth leakage or short circuit of a signal line would not turn the input circuit on. That's why it's considered as one of the safer connection methods.[Figure 4]
Mr. Vex: I get it now! That means i can introduce products that support source logic to my customers who uses the source logic.
Miss. Ori: Most definitely. So which brushless motor will meet your customer's needs?
Mr. Vex:Let me think... The BLE and BLF Series!
Miss. Ori:That is right. These product are made to support both the sink and source logic.So, what is the drive requirement in this case?
Mr. Vex: Customer require output power is about 120W and the maximum required speed is 4,000r/min.
Miss. Ori: For 120W, the latest BLE Series would be good. But what if higher output is require?
Mr. Vex:The BLF Series can provide up to 400W.
Miss. Ori: That's right!
Mr. Vex:Thank you. With the added knowledge i will be able to recommend the product now.