halvor_sens

R3 (Shutter Speed Selector) and L1(Shutter Coil) are part of the Camera. Please do not use D1, this is just a test LED.

Sorry to be a little late Richard, but you still have the same problem?

<p>New circuit in place.</p><div></div>

<p>Bronica with new circuit.</p><div></div>

<p>EC with old circuit.</p><div></div>

<p>Simulation file cannot be added here.<br> I could send it by mail.</p>

<p>I added the circuit with the colors of the wiring.<br> In fact you only have 4 wires to connect.<br> The wire between the variable R to +6V is in the camera as is the wire between the electromagnet and the ground.</p> <ol> <li>Yellow comes from the Var. Resistance (shutter speed selector) and goes to pin 6 and 7 of the chip.</li> <li>Orange is the contact that gives +6V as soon as you fire the shutter; it stays under tension until the cycle closes. Is goes on pin 4 and 5 and R1 and R2 and (already in place) on R3 (shutter speed)</li> <li>Black is the ground and is on pin 1 and the minus of the Elco C1.</li> <li>Brown is on one of the poles of the electro magnet and the diode. It goes to pin 3.</li> </ol> <p>You can download simulation software called LT Spice from "Linear Technology" (free software) to see what happens if you change R3 (shutter speed resistance). You will see that the shutter speed varies just like it should in the simulation.<br> Use the Bronica4.asc file to do the simulation. In stead of the electromagnet it contains a LED and R7 for the correct simulation.<br> Good luck and let me know if it works. I included some more pictures.</p> <p>Regards,</p> <p>Halvor</p>

<p>Great.<br> If you have any problems, just let me know.<br> I might have most of the parts as spares, so if you can't find them let me know. They cost a few cents...<br> Can you send me a picture of the inside of your EC? Is it exactly the same as mine?<br> I can send you the cable connections (colors) I used in my EC , if you want.<br> There is no further adjustment needed, because the C and R's are well dimensioned. I tested some longer timings and they were spot on! <br> Good luck and let me know if it works.<br> By the way, the problem is not in your battery connections or so? Does the little green lamp glow if you push the button?</p> <p>Halvor</p>

<p>Yes Vaidotas,<br> I made a lot of pictures since the repair and everything works!<br> The new little electronic circuit does the same as the old one and costs only a few Euro.<br> Happy to help you!<br> Where are you from?</p> <p>H.Sens</p>

<p>Diafragma parts of the lens.</p><div></div>

<p>You could also try to take the lens apart and clean the diafragma parts with alcohol.<br /> After assembly your lens will probably work correctly.<br /> I did this on a Nikkor-Q 13,5 cm lens for a Bronica. The lens is perfect now!<br /> You would need a few small screw drivers, a lot of light and some patience.<br /> See picture diafragma.</p> <p>HS.</p>

<p>Hi Amanda,</p> <p>I got a Bronica S with some problems. I managed to repair it by opening the side of the camera. <br> If you do so, you need a smaal screw driver and remove some parts of the "leather look". Remove the side of the camera.<br> Then you can see what is wrong. It could be cleaning and a little lubrication. I don't think there is a lock mechanism for the shutter selector.</p><div></div>

<p>Here is a picture of the repaired Bronica EC.</p><div></div>

<p>Hi.<br> Fantastic news! I managed to repair my old Bronica EC.<br> A small electronic print with the "timer" (PST 090) on it was not functioning. <br> This part is not available anymore, so with the help of another electronic circuit forum, I built a small circuit based on a NE555 chip. <br> It looks like this works. I am trying my first film now!<br> Happy to share the design; parts are cheap; less than 2 euro.</p> <p>Regards,</p> <p>Halvor</p> <p> </p>