Scope Clip Probe
what would make my VFD output freq read high?
I am using a Fluke 192B scopemeter (o-scope) to measure the output frequency of a Yaskawa F7 drive vs the 0-10v frequency reference. The drive says it's outputting 7.25Hz, but the scopemeter reads 2Khz, with intermittent dips. Maybe I have the scope leads wrong? I have the clip on earth ground (or in air, reads the same) and the probe on one phase of the drive output. Maybe there's too much switching going on in the drive to create a single "sine" wave period and the scope is reading all the switches? Maybe I need to use a scope with a filter? Whats going on here?!
The VFD output voltage waveform is pulse width modulated and you are probably reading the switching frequency. You should use a filter.
Edit1
The F7 is a PWM VFD with a default carrier frequency of 2kHz for all ratings. Refer to the user manual for carrier frequency adjustment information.
A look at what is currently available on eBay
 Brand new Two Oscilloscope Scope Clip Probe 100MHz Kit US $11.49 
|
 10 X Oscilloscope Scope Clip Probe 100MHz Tektronix HP US $79.99
|
 2 X Oscilloscope Scope Clip Probe 100MHz Tektronix HP US $16.99
|
 12 pcs 100MHz Scope Clip Probes for Oscilloscope Grey US $99.35
|
 2 pcs 100MHz Scope Clip Probes for Oscilloscope Grey US $16.19
|
 New 10x Oscilloscope Scope Clip Probe 100MHz Kit US $62.00
|
 New Two Oscilloscope Scope Clip Probes Probe 100 MHz kit US US $10.99
|
 Two 100MHz Oscilloscope Scope Clip Probes Probe US US $12.59
|
 New Two Oscilloscope Scope Clip Probe 100MHz Kit US $17.99
|
 100MHz Oscilloscope Scope Clip Probe Measurement Test US $7.99
|
 20MHz Oscilloscope Scope Clip Probe Measurement Test US $6.99
|
 Oscilloscope Scope Clip Probe 100MHz For Tektronix HP US $9.99
|
Items recently purchased from this site
20 Oscilloscope Scope Clip Probe 200MHz Kit new, 10pcs NEW x1 x10 UT-P05 Two Oscilloscope Scope Clip Probe 200MHz Kit , New 22 pcs Oscilloscope Scope Clip Probe 100MHz Kit F/S, 12 pcs 100MHz Scope Clip Probes for Oscilloscope Grey, 20 Oscilloscope Scope Clip Probe 100MHz 1x & 10x P6100, 10 x 100MHz Scope Clip Probes for Oscilloscope Grey, 6, HANTEK Oscilloscope Scope Clip Probe 200MHz Kit SALE, 6 HANTEK Oscilloscope Scope Clip Probe 200MHz Kit SALE, 6x HANTEK Oscilloscope Scope Clip Probe 200MHz Kit SALE, 10 X Oscilloscope Scope Clip Probe 100MHz Tektronix HP, 5 pair New 100MHz Oscilloscope Scope Probes w/Clip P6100, New 10 pcs Oscilloscope Scope Clip Probe 100MHz Kit F/S, TEN Oscilloscope Scope Clip Probe 100MHz 1x & 10x P6100, 10pcs x1 x10 Oscilloscope Scope Clip Probe 100MHz Tektronix HP, 2 Oscilloscope Scope Clip Probe X100 Max2000vDC HANTEK, 6 Six Oscilloscope Scope Clip Probe 100MHz Kit SALE NIB, New 10x Oscilloscope Scope Clip Probe 100MHz Kit, ESI 143 Automotive Test Lead Back Probe Gator Clips Kit for MultiMeter & Scopes, ESI 142 Pro Test Lead Kit w/ Pouch Piercing Clips Back Probe for DMM & Lab Scope, 2pcs High Quality Oscilloscope Scope Test Clip Probe 250 MHz Free Shipping, 6 HANTEK Oscilloscope Scope Clip Probe 60MHz Kit SALE, 6x Oscilloscope Scope Clip Probe 100MHz Kit SALE Hantek, 2x Oscilloscope Scope Clip Probe X100 Max2000vDC HANTEK, 2 pcs Black 100MHz Scope Clip Probes for Oscilloscope, New Two Oscilloscope Scope Clip Probe 200MHz Kit 600V, 2 HANTEK Oscilloscope Scope Clip Probe 200MHz Kit SALE, Two Oscilloscope Scope Clip Probe 200MHz Kit new, New Two Oscilloscope Scope Clip Probes 200MHz Kit 600V P6200 USA Seller, 6x HANTEK Oscilloscope Scope Clip Probe 60MHz Kit SALE, 5,40MHz Oscilloscope Scope Crocodile Alligator Clip BNC Connector Probes 600V n, High Quality Oscilloscope Scope Test Clip Probe 250MHz, 4 100MHZ x10 x1 Oscilloscope clip probes Agilent scope, 4 pcs 100MHz Scope Clip Probes for Oscilloscope Grey, 2PCS 100MHz BNC TO Test hook Alligator clip Scope Clip Probes for Oscilloscope, 2 pcs 100MHz Scope Clip Probes for Oscilloscope, PAIR UNI-T 200MHz Oscilloscope Scope Clip Probes Kit BNC X1/X10 UT-P05 for FLUKE, 2 pcs 100MHz Scope Clip Probes for Oscilloscope Grey, G89018 Tektronix P6000 Scope Probe w/Ground Clip, Pair 200MHz Oscilloscope Scope Clip Probes , 2X BNC 100MHz Scope Clip Probes Cables for Oscilloscope, 2pc BNC TO Oscilloscope Scope Clip ProbeS 100MHz Cables, Pair 150MHz Oscilloscope Scope Clip Probes , Two New 100MHz Oscilloscope Scope Probes w/Clip P6100, 2pcs High Quality 100MHz Scope Clip Probes , PAIR UNI-T 100MHz Oscilloscope Scope Clip Probes Kit BNC X1/X10 UT-P04 for FLUKE, Two Oscilloscope Scope Clip Probe 100MHz 1x & 10x P6100, New Two Oscilloscope Scope Clip Probe 100MHz Kit, New 2 pcs Oscilloscope Scope Clip Probe 100MHz Kit F/S, BNC Male Check Tool Passive Oscilloscope Probe Scope Clip 100MHZ , x1 x10 Oscilloscope Scope Clip Probe 100MHz Tektronix HP, 2 X Oscilloscope Scope Clip Probe 100MHz Tektronix HP, New 200MHz Oscilloscope Scope Clip Probes Kit Probe Super, New 2 Oscilloscope Scope Clip Probe 100MHz Tektronix HP, New 2 pcs 100MHz Oscilloscope Scope Clip Probe Kit, Two Oscilloscope Scope Clip Probe 100MHz Kit USA Seller NEW, Brand new Two Oscilloscope Scope Clip Probe 100MHz Kit USA Seller, New Two x1 x10 Oscilloscope Scope Clip Probe 100MHz Tektronix HP, PAIR UNI-T 60MHz Oscilloscope Scope Clip Probes Kit BNC X1/X10 UT-P03 for FLUKE, Check Tool 100MHZ Passive Oscilloscope Probe Scope Clip, Two Oscilloscope Scope Clip Probe 100MHz Tektronix HP, Top Quality 100MHz Oscilloscope Scope Clip Probe HP TEK, New 2x Oscilloscope Scope Clip Probe 100MHz Kit, New Two 2x Oscilloscope Scope Clip Probe 100MHz Kit HP Tektronix , 2pcs 40MHz Oscilloscope Scope Crocodile Alligator Clip BNC Connector Probes 600V, 100MHz Oscilloscope Scope Clip Probe Measurement Test, 2 PCS 60MHZ x10 x1 Oscilloscope Clip Probes Scope Kit, Two 100MHz Oscilloscope Scope Clip Probes Probe US , HP / Agilent SMD Clip, P/N 5063-2149 for Scope ( Oscilloscope ) Probes NEW, Brand new Two Oscilloscope Scope Clip Probe 100MHz Kit, New Two Oscilloscope Scope Clip Probes Probe 100 MHz kit US, Tektronix Oscilloscope scope probe P6028 with clip #3/3, New Oscilloscope Scope Clip Probes Probe 100MHz Kit, Pair 60MHz Oscilloscope Scope Clip Probes , Pair 100MHz Oscilloscope Scope Clip Probes , 100MHz Scope Clip Probe for Oscilloscope x 2 Pcs, Oscilloscope Scope Clip Probe 100MHz For Tektronix HP,
You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
