Opto-Diode or Opto-Coupler? OZ100SG or OC100HG? What's the Difference?

Sometimes people stop at the first word they encounter in a phrase and call it good.  I know I did for a while.  The phrase “opto-coupler” had been stored as ‘opto-something’ in my brain because the only opto-anything I’d ever worked on was an opto-coupler.  So when VMI came out with an opto-diode, it took a little while to adjust.

I knew I wasn’t the only one to experience difficulty with part numbers when several colleagues responded sympathetically as I hopelessly mixed them up in various internal and external correspondences.  To their credit, the Sales department was very patient with me.  Was it an OZ100HG, or OC100SG?  I knew I had the “100” part right, but that was about it. 

For the record, the correct part numbers are OZ100SG, and OC100HG.  Here’s a breakdown of what the part designators mean -



OZ100SG - 10kV Opto-DIODE

The OZ100SG is a stand-alone opto-diode.  “O” stands for “opto”, “Z” indicates the body size; “100” stands for 10kV Vrwm, and “SG” indicates Vf, Ir, and Trr, are identical to the discrete, glass body Z100SG diode. 

On the other hand, the OC100HG is an opto-coupler, as indicated by “OC”.  It has a Vrwm of 10kV as evidenced by the “100”.  “HG” stands for “High Gain”. 



OC100HG - 10kV Opto-COUPLER

Another important distinction is package size.  The OZ100SG is much smaller since the only thing in it is a z-body, multi-junction, high voltage diode that has been specially passivated and is super sensitive to light.  The diode is over-molded in an optically clear compound.  The OZ100SG has two terminals – anode and cathode.



The OC100HG, on the other hand, contains an opto-diode of sorts, and two LEDs that serve as an integrated light source.  It is much larger than the OZ100SG.  

Got all that?  No worries if you don't.  Just give us a call.

·         OZ100SG – 10kV opto-diode

·         OC100HG – 10kV high gain opto-coupler

·         Z100SG – 10kV high voltage diode

How Do You Know When Something is Up?

Sometime ago now, VMI was inundated with requests from all over the world for exactly the same products in exactly the same quantities and exactly the same delivery schedule.  The requests were steady – one or two here and there, but they kept up over a period of several months.    Trust me when I say, “red flags were triggered”. 

Now, for all of you requesters out there, you might want to take note for potential ways to mix it up and fool us, but good luck with that.  We’re a mid-size company, and we still talk to each other.  Sales talks to Engineering; Engineering talks to Purchasing; Purchasing talks to Production; Production talks to Sales who talks to Purchasing who talks to Production who talks to Engineering….you get the point.  

Many of the requests came through our U.S. and international sales representatives; some came directly to the factory.  They all had several things in common.  And we noticed.

So how do you know when something is up?  It’s always interesting to find out about different projects and applications, and it doesn't hurt to ask, but you don't always get answers.  In this case, we never did hear what all the brouhaha was about.  We detected commonality in the product mix, quantities, and requested delivery dates.  Patterns started to emerge, and when you hear the same thing from multiple and varied sources, you sit up and take notice. 

The second point to all this is that VMI has really good internal communication.  We know and appreciate the value of that.  If a company doesn’t have good internal communication, it's efficiency goes down.  Everyone suffers.  Boo-boos go up, and so does the number of ‘embarrassing situations’. Unless you thrive on crisis management (some folks do, personally I'm not one of them), you probably don't like to deal with those situations either. 

Good internal and external communication is especially critical during the design and development phases of custom devices.   Things change fast.  Tracking materials, purchase orders, sales orders, revision levels, processes, process changes, and so on, can be daunting tasks.  This is one of the reasons VMI has been so successful in custom solutions.  We talk to each other, and we talk to you.

Choose Your High Voltage Power Supply Design Team Carefully

What do microwaves and high voltage power supply design have in common? Well, they’re both specialty fields, and they both operate according to a slightly different set of rules (unless you want to get zapped, of course).

High voltage design differs from low voltage design, too. Component characteristics like dielectric strength, isolation voltage, and parasitic capacitance, can often be ignored in low voltage applications. Ignore them at your own risk in high voltage applications, because strange things can happen.

Many are familiar with high voltage/ high power found in power distribution. Many may not be familiar with the high voltage/low power category. Ion generation, image intensification, medical devices, high-end laboratory instrumentation, and high-tech wafer fabrication equipment are all examples of high voltage/ low power applications.

Fortunately, because it is a niche field, custom designed power supplies and high voltage blend together nicely.

HV power supply design can be complex. One way to mediate design complexity is to stay close to the design team. It will be easier to communicate your specifications. Voltage Multipliers Inc.’s power supply design engineers are readily accessible and easy to contact. Often transparent to the customer, engineers are part of the Sales, Purchasing, QA, and Production, design team. Cross-discipline involvement in the beginning means Design-for-manufacture is easier to implement when the time comes, rather than as an afterthought.

With more than 50+ years of combined experience in high voltage power supply design, VMI engineers work directly with customers to ensure their design goals are met.

Project specifications range up to 125kV and 50W in applications as varied as industrial, agricultural, medical, commercial, and military.



Custom Designed High Voltage Power Supplies



When you look for high voltage power supply designers, important things to consider include the company’s methods of design verification, prototype capability, design-for-manufacturability skills, the ability to transition from prototyping to production scale, and standard & custom testing.

Design cycles can be long or short. While not exactly moving at the speed of lightening, a design cycle of six months from conception to production is typical. That might sound like a long time by internet standards, but considering all that goes into it, it’s pretty darn fast.

 There are other power supply design choices, some with stronger name brand recognition or stronger distributor relationships. However, none of them will give you the level of service or design expertise VMI customers have come to expect. Problem-solving is our forte.

VMI is ISO9001:2008 certified.