Help with Circuit Design

I haven't designed a circuit in more years then I care to mention so I know I need help. What I want to do is .. control a table saw and a shop vac. When I turn the circuit ON...table saw and shop/vac on immediately When I turn the circuit OFF... table saw off immediately and shop/vac to run for approx. 5 seconds longer and then turn off. If your able and/or willing to help I'll give you the specs for both pieces of equipment.

Reply to
buyem
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At it's crudest level...

2 relays, a diode, resistor and a capacitor..

D from BC

Reply to
D from BC

Just go here:

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and search for H3DE timer. It does exactly what you want.

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John B
Reply to
John B

Your table saw switch already does exactly what you want it to do for the table saw. For the shop vac, all you need to do is connect a timer relay as mentioned in the other posts to the "output" of your table saw switch.

Chuck

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Reply to
chuck

You only need one relay - for the vac. Also, you will need a rectifier and transistor to drive the relay.

Tam

Reply to
Tam/WB2TT

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Why not just use a normal relay (or just a switch) for the table saw
and an off-delay relay for the shop-vac?  
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Reply to
John Fields

Basic Stamp.

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Many thanks,

Don Lancaster                          voice phone: (928)428-4073
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Reply to
Don Lancaster

Sears sells a plug in box that does just that. Of course you could roll your own. I would start by detecting the current in the table saw circuit, then have a relay close energizing a second feed to the shop vac. I know my shop vac is something like 13A, and my saw is probably close to 15A therefore I suggest using two separate feeds.

Reply to
scada

Search for a delay off timer.

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Reply to
Homer J Simpson

On Sat, 20 Jan 2007 10:28:32 -0700 in sci.electronics.design, Don Lancaster wrote,

Hah! A 555 would be cheaper.

Reply to
David Harmon

Go to this link

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and look for "Power Off Time Delay Relay Circuit" near the bottom

Reply to
kell

I second that but use 1 solid state relay, 1 diode , 2 resistors (voltage divider) and 1 capacitor..... bobs your uncle.

Reply to
ericwhit
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Thanks for the suggesti>

Reply to
buyem

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