Alex Zoghlin <[email protected]> writes: > The easy answer is to always use a separate pyro circuit, but that isn't > always feasible.
As Bdale says, there's a special circuit on our boards designed to prevent brown out which was first included in TeleMega v1.0. The TeleMega v1.0 design was finished just before Bdale's house burned to the ground and while we replicated most of that circuit to all of our other products, we lost one critical change to a existing resistor value, and so some of our board designs didn't get that updated until the recent round of revisions. Boards with working brown-out prevention circuit: TeleMega: All versions EasyMega: All versions TeleMetrum: v3.0 TeleMini: v3.0a EasyMini: v2.0a I've fixed a few older boards; it's a pretty easy thing to do if you're comfortable reworking 0402 passives; the current limiting resistor to the gate of the pyro FETs needs to change from 100Ω to 1kΩ to keep the current through the comparators within limits. Without that change, the FET may keep firing even when the comparator tries to keep it off. -- -keith
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