According to the cubesat design specification electrical requirements (3.3.7 in revision 13) a Cubesat shall include an RBF pin:
3.3.7 The CubeSat shall include an RBF pin.
- 220.127.116.11 The RBF pin shall cut all power to the satellite once it is inserted into the satellite.
- 18.104.22.168 The RBF pin shall be removed from the CubeSat after integration into the P-POD.
- 22.214.171.124 The RBF pin shall protrude no more than 6.5 mm from the rails when it is fully inserted into the satellite.
I'm wondering how these kind of RBF pins are realized according to the cubesat standard, but also whether there are other mechanisms that have been used in other missions.
I tried doing extensive internet searches, especially for publications or technical documents, as I am very much interested in the actual electrical solution of a RBF pin and whether anyone ever tried a solution where for example you don't pull something out but put something in.
From what I gather even if you put in an RBF pin according to the cubesat standard there are still currents flowing around, as the RBF pin is to short the Base and Collector of a transistor thus preventing it from opening. But this needs pull up resistors and causes current bleed even if the satellite is to be off. It seems kinda silly to have a constant power flow that drains your batteries when you don't want the satellite to do anything.
Could anyone tell me of other RBF pin mechanisms, specifically ones where there is a galvanic isolation of the batteries and the rest of the satellite using an RBF pin? I'd be very happy about technical documents or papers that I could look into.