Relay-Based Multivibrator

This can work, but not sure if this is what you are looking.cap can be used to change frequency.

better one with diode.

kaztronics; sound like a forward/reverse set up for motor/s? they are interlocked with normally closed switches, & held in place with normally open switches, only one can closed at a time, the time delay may allow the motor to stop/slow down before reversing it. perry

you're close Perry, they drive hydrolic system that moves the table on the grinder.

Have to figure out how they're activated. I see there is another delay relay, switching on/off as limit switch is activated.

Thanks for the input guys.

Kaz

Regards.

<< they drive hydrolic system that moves the table on the grinder >>

Limit switches on both ends are used in such cases as:

Up-Down or left-right movements. In case of heavy loads if Micro-switches are used operate a relay to switch the load.

<< Have to figure out how they're activated >>

One way is as you pointed out; another delay relay but the end-limit swich is a change over switch which cuts the circuit of previous movment & connects the reverse movement circuit.

Relays may perform multi-jobs as they may have more poles or 2 or more CO-MP switches can be used.

Relays are preferred because in case of failure of switch will produce a complicated fault while failure of a relay will give a clear fault.

Have a fine day !!!!!

I may be poking my nose in here unwanted, apologies if true.....but:-

Do you need to use this relay system for reasons of cost or historical value?

Because if not, I would replace it completely with something modern.

If for example its a CNC machine, then modern servo systems or stepper systems would do a far better, cheaper and more reliable job!!!!

You did not give enough details for me (or anyone else!) to be able to be more specific.....

I think you're working on a horizontal grinder, and the circuit controlling the traverse movement fails to swing the table, if this is the case just disconect both (left-move & right-move) solenoids from the old control and conect them to the smallest, cheapest PLC with relay outputs and program it to alternate both solenoids when the proper limit switch (connect these to 2 inputs) is activated during cycle.

If the feed valve is solenoid actuated, then generate a pulse after each stroke for it, so the table "steps" normally and the metal is not rectified over and over in the same span.

But if the feed valve is "pilot" controled by the swing valve, then leave it as is, it should work. (if it is pilot controlled, it has no solenoid).

Yahlasit

Finally after a couple of modification the machine seems to be working, but believe me, it was a nightmare to work without documentation, pulling all those wires to make a sketch to figure out how it works.

Thanks to all that gave their input.

What is it? I did not see anywhere where that was stated....

SEVA polishing machine.

Regards.

Siemens had been manufacturing X-Ray Plants [1970/80s] having the complete automated Exposures as short as a part of a second in KW range with hundreds of relays in control circuit & also Auto Cut-Film-Changers with sme technology.

If you can approach them ask for the circuit diagram of ''Helliophose''.

May have a luck !!!!!

Relays are interesting do the reverse engineering on this and come up with a schematic.

Use a "clip-clop" circuit.

• Big electrolytic capacitor.
• Two DC relays, each fitted with freewheel diodes across their coils.
• Relay 1 coil is wired from the + volts of the supply in series with the + terminal of the capacitor. The - terminal of the capacitor is down to supply 0-volts.
• Relay 2 is wired across the capacitor, respecting the polarity of both.
• Introduce two switch contacts. The normally closed contact of relay 2 disconnects the current flowing through relay 1 coil. The normally closed contact of relay 1 disconnects the current flowing through relay 2 coil.

Energise, and watch in amazement.

you could work in a museum

You have to draw the circuit and refine it to the understandable schematic symbols and then upload it for evaluation. Without making any mistakes or comments or interpretations or variations.

16 years late, that a long slumber my friend