Re: Something has been blown
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Ceasar It might be worthwhile to make up a little test jig for evaluating IRF510 devices.? Maybe just a pot to vary the gate bias and a 1K resistor in the drain lead.? Ground the source lead.? Monitor drain voltage as you vary the gate bias.? At between 3 and 4 volts on the gate you should see drain voltage decrease indicating that the device is drawing current.? If this current is not adjustable it might indicate a defective device.? Of course this is just a DC test and not fully representative of RF performance. ? In BJT (Bipolar Junction Transistors) we are used to seeing the base draw current to forward bias the device, but with MOSFETs there is no gate current.? They are only affected by voltage at the gate.? Once we accept that it is easier to troubleshoot circuits that have these devices. An oscilloscope or RF Detector Probe could be used to measure RF at various points around the IRF510 devices.? You should have at least a couple of volts RF on the gate lead, and more RF volts on the drain lead.? If nothing on the gate then you could use the probe or scope to verify presence or absence of RF voltage in the drive section. Arv _._ On Fri, Jan 26, 2018 at 9:23 AM, C¨¦sar EA3IAV <Cesarleon@...> wrote: Thank you Arv |
