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schematics and layout work
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Prototype Latching Circuit #6

Open gabesoares opened 6 years ago

gabesoares commented 6 years ago

Order components and prototype JK flip flop latching circuit - this will be used on the output fault signals of the AMS, IMD, and BSPD 1517718636686-1951242273

gabesoares commented 6 years ago

Desired operation: fault signal is sending 0, all is good, then a fault occurs and the signal sends a 1 (+5V) for a second and then drops back to 0.. We want this 1 to stay latched forever...

JK Flip Flop Logic: If J=0, K=0, then output Q (& Q bar) stays latched to whatever it was before If J=1, K=0, then output Q is set to 1, and Q bar is set to 0 If J=0, K=1, then output Q is set to 0, and Q bar is set to 1 If J=1, K=1, then output Q and Q bar are both toggled to the opposite of what they were before

NOTE: A clock signal is needed for the JK flip flop, a 555 timer can be used to generate the clock, but the exact circuit will need to be looked up

The push button attached to the K input will allow the output Q to be reset to 0, and Q bar to be reset to 1. The red error LED should light up if the fault signal sends a 1 and the output is latched, and turn off when the push button (reset) attached to the K input is pressed.

The green LED should be on in normal operation, and as soon as the fault signal sends a 1, it should stay off until the reset push button is pressed. (This green LED simulates the relay coils of the AIRs)

gabesoares commented 6 years ago

Prototype this latching circuit as well, talk to Will to learn more about it:

img_20180204_103441

Will-McKnight-604 commented 6 years ago

Updated Latching Circuit

20180214_082955

gabesoares commented 6 years ago

Latest latching circuit img_20180213_143020

gabesoares commented 6 years ago

Will need high side driver instead of FET, since vgs will be tough to get without a charge pump, especially with a microcontroller output:

This one looks good, Rds(ON) a little high but not really significant for low current and turning on a relay, it also has a lower pin count and less external components than the other automotive TI ones http://www.ti.com/product/tps1h000-q1

Will-McKnight-604 commented 6 years ago

Hanieh is taking the flip-flop circuit and prototyping that one, I'll be doing the latest latching circuit