In part 1 we introduced cue light systems and discussed simple 2-wire a.c. systems. In part 2, we introduced d.c. switching and moved on to latching STANDBY. Later in part 2 we introduced a microcontroller-based design. In this part we will consider adding MASTER GO to relay systems and then expand on microcontroller-based designs. Note… Read More: Theatrical cue lights – part 3 »
In the first part, we covered an introduction to cue lights are and how they are used. We also looked at a simple two-wire system. In this part we are going to look at three-wire systems with automatic flashing. Note that the circuits presented here are not complete designs and there are many and varied… Read More: Theatrical cue lights – part 2 »
Some years ago I designed a theatrical cue-light system and I recently came across the drawings. The system was based on relays and I thought it would be interesting to see how cue-light designs have progressed over the years. I found that there are many different ways of doing cue lights and I thought I… Read More: Theatrical cue lights – part 1 »
I was asked to comment on whether the Phantom Piezo Preamp (available in the shop here) is suitable for connecting to a balanced piezo transducer as covered by Chrisitan Liljedahl here. The short answers is yes, absolutely – the Phantom Piezo Preamp has balanced input and output and effectively you connect a single or double… Read More: Balanced piezo transducers »
I had an enquiry (which which puzzled me slightly) about using LED’s to protect the input of the Phantom Piezo Preamp (available to buy in the shop here). However it was noted that if a piezo transducer is dropped onto a hard surface, the voltage spike generated could be high enough to damage downstream electronics.… Read More: Protecting piezo preamps »
You may have gathered from my last-but-one post on bit-banging the AD9833 DDS module that I have been playing with audio oscillator designs. As part of this process, I have tried a few Wien bridge oscillator designs that purport to not require a proper non-linear device (such as a miniature lamp or an RA53 thermistor).… Read More: Wien Bridge Oscillator »
Since Fairchild finally discontinued the 2N5457 JFET along with a number of other JFETS in the TO92 package, prices have been rising and tales of fakes have been increasing on audio and stomp-box forums. You can still buy the 2N5457 from Central Semiconductor, but they are very expensive – too expensive for Stompville to consider… Read More: Substituting the 2N5457 »
I bought an AD9833 DDS module from China – you know the one: I wanted to control it from an Atmel ATtiny and my weapon of choice was the ATtiny44. Now I could just have easily used an ATtiny2313 (both devices are 14-pin), but I didn’t – and I went on and built a PCB.… Read More: Bit-banging the AD9833 DDS module »
Alan Wolke (W2AEW) has posted an excellent tutorial on YouTube covering an introduction to the theory and operation of JFETs and MOSFETs. I highly recommend this video.
Following on from my previous blogs about Connecting Loudspeakers to Amplifiers and Passive Dummy Loads for Amplifiers here is a project for a modest passive dummy load with a twist – I have included a differential ‘scope probe to facilitate monitoring of the signal on an oscilloscope. I managed to score a new-old-stock Grayhill switch… Read More: Passive Dummy Load Project »