memory

A

arivel

Member

• Oct 28, 2020

• #21

alternatively there are memories with parallel inputs and transparent parallel outputs?
is it possible to exploit the signal of inputs 40193 to also control the memory?.
it goes without saying that I use the two "UP / down" inputs (pin 5-4) and then, when the power supply returns, the "LOAD" input (pin 11).

 

gophert

Well-Known Member

Most Helpful Member

• Oct 28, 2020

• #22

arivel said:

alternatively there are memories with parallel inputs and transparent parallel outputs?
is it possible to exploit the signal of inputs 40193 to also control the memory?.
it goes without saying that I use the two "UP / down" inputs (pin 5-4) and then, when the power supply returns, the "LOAD" input (pin 11).

Click to expand...

See post #7

 

unclejed613

Well-Known Member

Most Helpful Member

• Oct 28, 2020

• #23

see if there are still some "bubble memory" devices around, they were an early form of NVRAM using magnetic domains. while the power was on, they operated as RAM, if the power failed, they maintained their state.

 

rjenkinsgb

Well-Known Member

Most Helpful Member

• Oct 29, 2020

• #24

Can't you use bistable relays with two sets of contacts?

You can use one set for the system outputs and the other set for feedback to the electronics, to capture the state when the device is switched on again.

Sequence the power-on so you generate a load pulse before power is applied to the relay drive circuit, so the counter always restarts at the correct value.

 

A

arivel

Member

• Oct 29, 2020

• #25

usually they are almost all 2 contacts and for what I have to do I am already used.
i looked for 3 and 4 contacts but the first type is non existent and the second is expensive.

 

rjenkinsgb

Well-Known Member

Most Helpful Member

• Oct 29, 2020

• #26

You could use a basic, cheap relay for the two (or more) external outputs, run from one contact on the bistable relay.

That would leave a free contact for re-loading.

 

rjenkinsgb

Well-Known Member

Most Helpful Member

• Oct 29, 2020

• #27

Or another thought - if the "load" will always be powered when the logic circuit is, you could use optoisolators to sense power from the output relay contacts and provide the reload data.

 

ChrisP58

Well-Known Member

Most Helpful Member

• Oct 29, 2020

• #28

The 40193 is a four bit counter. How many bits are you trying to store?

 

A

arivel

Member

• Oct 30, 2020

• #29

there are two 40193s in cascade.
I'm interested in 6 bits.

 

gophert

Well-Known Member

Most Helpful Member

• Oct 30, 2020

• #30

arivel said:

there are two 40193s in cascade.
I'm interested in 6 bits.

Click to expand...

Is it a battery device or AC device? How long do you expect to be without power when in the off state?

 

A

arivel

Member

• Oct 30, 2020

• #31

it is not a battery operated device.
how long? .
there is no fixed period.
it can vary from a few days to a few weeks