There are two reasons for this: (1) that the effective gate/channel area is so large that the associated capacitance is high, which would then require a relatively large inadvertently applied static charge to generate a destructive gate/channel voltage (typically >40 V), and (2) that such protective diodes could, if they were triggered into conduction, cause the MOSFET to act as a four-layer thyristor and become an effective electrical short circuit. In power MOSFETs, these protective devices are seldom incorporated into the chip. These could be either zener diodes or simple junction diodes connected between the gate and the source or the source and drain, as shown in Figure 9.19. Quote Because it is theoretically possible for an inadvertent electrostatic charge, such as might arise with respect to the ground if a user were to wear nylon or polyester fabric clothing and well-insulated shoes, it is common practice in the case of small-signal MOSFETs for protective diodes to be formed on the chip at the time of manufacture. Both ways, source impedances will be less than 10% of F.X. loop send is after tonestack recovery stage or after O.D. I don't know how much this tonestack loads C.F. loop input impedance is so high that it may not interfere with gain after tone stack. which sources a low impedance into a heavy load as tonestack, but I believe F.X.
which is high enough to be fed from a source such as C.F. loop input is high impedance, according to the corresponding Merlin's schem and math, around 5Mohms. loop recovery stage which will alter and color sound effectively.į.X. loop is concerned, it should not 'color' your tone, although losses thru tonestack may be recovered at F.X. loop recovery, power tube grids.Īs far as a F.X. GT input, gain, gain, C.F., tonestack, F.X. If I understood what you mean you will have: Sorry but I did not understand what you meant by problem here. Will post the entire circuit in a couple of days before the final component order(s). I'm polishing up a circuit that got started a long time ago and has been sitting on the shelf for too long. The basic concept is that the grid (gate) of the cathode follower will be at B+ until the cathode of the preceding triode warms up and pulls the voltage down, while the cathode (source) of the cathode follower is at ground potential creating a BIG voltage drop across the grid (gate) and the cathode (gate). Keen's suggestion of using a MOSFET to replace the tube triode in a DC coupled cathode follower. On a closely related topic, if I use a MOSFET like an IRF820 or a ZVN0545A, is there a need for a 12 volt zener between the gate and the source or is that diode already included in these MOSFETs? Sorry, but I can't remember where that circuit addition came from, but it was in the context of R.G. Is this more like a seatbelt or a 5-way racing harness for toodling around town? Rather than explain the theory in shorthand here, please look at Merlin's DC Cathode Follower page. Diodes may be any size, and while most diodes aren’t very big, they can be almost microscopically small.Someone here recently advised adding a protection diode to a cathode follower.
The entire assembly is surrounded in a glass or plastic covering. This material is typically silicon, but a wide range of different materials may be used. A device that blocks current in one direction while letting current flow in another direction is called a diode. The diode has two terminals, a cathode and an anode, that are connected by a small amount of semiconductive material. The physical construction of a diode varies slightly based on the reason for its use, but certain factors remain the same. It is the combination of these two elements that allows the diode to function. The cathode is the part of a diode that allows power to flow out, and an anode is the part that allows it to flow in. This process works in one way if a terminal takes in electricity, it doesn’t let power back through. These components have two terminals-one that takes in electricity and one that lets it out. A semiconductive diode is a basic component of a huge number of electrical systems.