I'm working on an amp repair that requires ZY5.1 zener diodes (5.1V zener voltage, 2W max, DO-204AM package). I can't find this specific animal from Digikey or Mouser in Canada. Any other suggested sources or alternative/equivalent parts? Thank you.
TL431 can make a 5.1V Zener ( adding two resistors ).
But, cannot do 2W because it is 100 mA maximum rating.
What is the power requirement in your circuit ?
But, cannot do 2W because it is 100 mA maximum rating.
What is the power requirement in your circuit ?
This Zener is larger than your original part but might be usable if it fits .
https://www.mouser.com/ProductDetail/ON-Semiconductor/1N5338BG?qs=y2kkmE52mdMKTkCzLxg8vA==
https://www.mouser.com/ProductDetail/ON-Semiconductor/1N5338BG?qs=y2kkmE52mdMKTkCzLxg8vA==
While I have a vague idea of what a Zener does, I'm not sure of what it's doing in this circuit. So please bear with me.
The amp is a NAD T762 It's D716 and D718 on page 58 of the service manual. In the schematic of the Main Board on page 38, you can see them in the bottom right (in the current orientation. Bottom left if you turn the schematic horizontally) feeding into the voltage regulators. But, beyond this, I'm unclear on the power req't.
Thanks for this. The Zeners are sandwiched between heat sinks on the voltage regulators and electrolytic caps. Both the zener and the heat sinks can get too hot to touch. I might be wise to revise the location of the Zeners so they are elevated above the heat sinks, or mounting them on the backside of the PCB. Either way, your suggestion might be a good option. Thank you.
The Zeners are just reducing the power dissipation in the voltage regulators by about half. Using the 5 Watt Zeners as replacements seems like a good idea since the power dissipation in the circuit is probably on the high side. Without knowing how much current each voltage regulator sources it is not possible to calculate the power loss in each component.
Thanks for that info, Bill_P. It looks like I should be able to mount it on the reverse side of the PCB. There isn't much in the way of air circulation for cooling, but it'll be the only component on that side of the board.