Original effects with schematics, layouts and instructions, freely contributed by members or found in publications. Cannot be used for commercial purposes without the consent of the owners of the copyright.
I love your idea, MicTester, as a neat and interesting alternative to the old 3PDT footswitch.
So I searched around for that particular latching relay. None available (apparently) in the UK. Similar types cost around £5-10 here (plus VAT and postage) !
Eventually found an eBay seller in Singapore, doing them for just under £1 each, including free shipping. I don't know if they'll ever turn up, but I'm an optimistic old devil.
”Sex is great - but you can’t beat the real thing !” - The Wanker’s Handbook
Lucifer wrote:
Eventually found an eBay seller in Singapore, doing them for just under £1 each, including free shipping. I don't know if they'll ever turn up, but I'm an optimistic old devil.
That's where I got mine too, but don't scratch the hoofs it may take a few weeks...
I'm using capacitors to replace my guitar effects and give more clarity to the sound.
The seller goes under the ebay ID of 'flute570606', and an email I received to acknowledge the order was from a guy named Chou (in Taiwan - not Singapore).
”Sex is great - but you can’t beat the real thing !” - The Wanker’s Handbook
mictester wrote:
The only addition I sometimes make to this circuit is to use a CMOS bistable to feed the anode of the diode - the "+" point. I use a 4013 configured with one side as a bistable (pin 1 or 13 feeds the switching circuit directly), and the other side as a power-on reset and debounce circuit, or I use a 4093 quad schmitt NAND with two gates for the bistable, one for debounce and one for switch-on reset. Either circuit then allows the use of a momentary switch.
Sorry for resurrecting such an old post, just wondering if you ever published an extended schematic to include the 4013 etc so we can use a momentary switch? Thinking about converting a couple of Ibanez pedals to true bypass without having to drill the case,
chris1001 wrote:
Sorry for resurrecting such an old post, just wondering if you ever published an extended schematic to include the 4013 etc so we can use a momentary switch?...
yep..
I think you may use one flip-flop output (transistor collector) to drive your relay control circuit. ( Just check the voltage drop from the collector resistor is not too high to prevent proper functioning...)
What's mic's 4013 does is just a flip-flop...
BTW Ibanez's LED indicator won't follow relay's operation and you'll have to figure out what to do...
A single schmitt inverter can handle power-on reset, debounce, and bistable flip-flopping duties simultaneously. If that schmitt inverter is a standard non-CMOS 555, it can drive the relay too: viewtopic.php?f=13&t=13295&p=156714&hilit=+555#p156714
rocklander wrote:hairsplitting and semantics aren't exactly the same thing though.. we may need two contests for that.
Does anyone socket the relays? I haven't found a 5 x 2 IC socket to fit it into - does it make sense to be able to sway out an electromechanical component?
The relay is on its own board and I want the switching currents to remain on that board for noise considerations.
Andrew.
Frankly, there's so little current drawn when the relay changes over, and even less in the quiescent state, I have yet to make a click or a pop with this circuit, even in very high gain effects.
Originally, this was a way to use up a whole drawerful of "Carling" footswitches that had been removed when doing "true bypass" modifications to Cry Baby pedals!
"Why is it humming?" "Because it doesn't know the words!"
I've built up this circuit using the 555 timer, bi-polar relay & momentary switch etc as drawn out previously by Bubstance on this thread. Out of the pedal it works fine, one thing I wanted to test was what would happen if the effect was 'on' and the power got pulled, would the relay switch over and default the pedal to the 'bypass'. When its just a lose assembly on the bench connected to nothing but power and a multimeter to check the relay operation it works fine, if I cut the power to it the relay switches over from 'on' to 'bypass'. However when conected to a pedal (with just the momentary switch and power connections from the pedal - no connections to the in/out jack sockets just yet), and I pull the power, the relay doesnt switch back to the 'off' state, its as though other components in the pedal are draining the capacitors in the bypass circuit enough to prevent the relay from switching over. So my question is, how can I segregate the power to the bypass circuit, or at least prevent residual current that is essential for the relay re-set from draining back into the main pedal circuit? Diodes on the +9v power feed to it dont help, but I suspect its more complex than that. Perhaps a much bigger capacitor than the 100uF on the bypass circuit?
After some more testing, its the 100uF cap in the pedal on the DC input (ripple filter) thats keeping the 555 alive for about 1/2 second. Need a way of instantly disconnecting the 555 from this cap when the power is pulled, or better still add a large value cap to the flip-flop circuit to make sure that can still function for a split second after the 555 has shut down. I suspect that what is happening is that the 555 shuts down after the flip flop and relay lose their power, hence no switching to 'bypass'.
chris1001 wrote:After some more testing, its the 100uF cap in the pedal on the DC input (ripple filter) thats keeping the 555 alive for about 1/2 second. Need a way of instantly disconnecting the 555 from this cap when the power is pulled, or better still add a large value cap to the flip-flop circuit to make sure that can still function for a split second after the 555 has shut down. I suspect that what is happening is that the 555 shuts down after the flip flop and relay lose their power, hence no switching to 'bypass'.
You could always try a 220K bleeder resistor across the DC filter cap. That should allow the cap to bleed off quickly.
chris1001 wrote:No joy, will try again using a 40106 Schmitt inverter and see how that copes with cutting the power.
Hmmm... what about adding a current steering diode that would force the relay or Schmitt into one state when the power was cut? That state would then become bypass.
