Hello guys,
I want to repair my old beloved Philips microvolt meter of which the modulator (chopper) mosfets have died. They were dual gate BSV81 mosfets and I decided to replace them with dual gate MFE201 mosfets, because that is the best I could buy. (Anyone with a couple of real BSV81 s?) They are only used as switches, so I decided to give it a try.
My problem is that the MFE201 has a different pin-out and that I cannot figure out which gate is which. I wonder if anyone can advise me on the subject. I have attached three pictures.
1. The concerned part of the circuit diagram of the voltmeter.
![aa.jpg aa.jpg](https://makerv2.webteractive.co/forums/data/attachments/37/37836-cee594dbc78e3fc364f96294e4f32d5f.jpg)
2. The pinout of the original BSV81
![ab.jpg ab.jpg](https://makerv2.webteractive.co/forums/data/attachments/37/37837-ca75f21b634c9e87c47406c09a27b584.jpg)
3 The pinout of the MFE201 that I found on the web.
![ac.jpg ac.jpg](https://makerv2.webteractive.co/forums/data/attachments/37/37838-b1013a8dee925b34fc6762e89a47bf1b.jpg)
Thank you reading this.
Best regards
Bob Andriesse
[Mod. edited to resize images]
I want to repair my old beloved Philips microvolt meter of which the modulator (chopper) mosfets have died. They were dual gate BSV81 mosfets and I decided to replace them with dual gate MFE201 mosfets, because that is the best I could buy. (Anyone with a couple of real BSV81 s?) They are only used as switches, so I decided to give it a try.
My problem is that the MFE201 has a different pin-out and that I cannot figure out which gate is which. I wonder if anyone can advise me on the subject. I have attached three pictures.
1. The concerned part of the circuit diagram of the voltmeter.
![aa.jpg aa.jpg](https://makerv2.webteractive.co/forums/data/attachments/37/37836-cee594dbc78e3fc364f96294e4f32d5f.jpg)
2. The pinout of the original BSV81
![ab.jpg ab.jpg](https://makerv2.webteractive.co/forums/data/attachments/37/37837-ca75f21b634c9e87c47406c09a27b584.jpg)
3 The pinout of the MFE201 that I found on the web.
![ac.jpg ac.jpg](https://makerv2.webteractive.co/forums/data/attachments/37/37838-b1013a8dee925b34fc6762e89a47bf1b.jpg)
Thank you reading this.
Best regards
Bob Andriesse
[Mod. edited to resize images]
Last edited by a moderator: